diff --git a/implementation-contributed/v8/mjsunit/harmony/to-primitive.js b/implementation-contributed/v8/mjsunit/harmony/to-primitive.js
deleted file mode 100644
index 8decb04657..0000000000
--- a/implementation-contributed/v8/mjsunit/harmony/to-primitive.js
+++ /dev/null
@@ -1,54 +0,0 @@
-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Flags: --allow-natives-syntax
-
-assertEquals(1, %ToPrimitive(1));
-assertEquals(1, %ToPrimitive_Number(1));
-
-assertEquals(.5, %ToPrimitive(.5));
-assertEquals(.5, %ToPrimitive_Number(.5));
-
-assertEquals(null, %ToPrimitive(null));
-assertEquals(null, %ToPrimitive_Number(null));
-
-assertEquals(true, %ToPrimitive(true));
-assertEquals(true, %ToPrimitive_Number(true));
-
-assertEquals(false, %ToPrimitive(false));
-assertEquals(false, %ToPrimitive_Number(false));
-
-assertEquals(undefined, %ToPrimitive(undefined));
-assertEquals(undefined, %ToPrimitive_Number(undefined));
-
-assertEquals("random text", %ToPrimitive("random text"));
-assertEquals("random text", %ToPrimitive_Number("random text"));
-
-assertEquals(Symbol.toPrimitive, %ToPrimitive(Symbol.toPrimitive));
-assertEquals(Symbol.toPrimitive, %ToPrimitive_Number(Symbol.toPrimitive));
-
-var a = { toString: function() { return "xyz" }};
-assertEquals("xyz", %ToPrimitive(a));
-assertEquals("xyz", %ToPrimitive_Number(a));
-
-var b = { valueOf: function() { return 42 }};
-assertEquals(42, %ToPrimitive(b));
-assertEquals(42, %ToPrimitive_Number(b));
-
-var c = {
-  toString: function() { return "x"},
-  valueOf: function() { return 123 }
-};
-assertEquals(123, %ToPrimitive(c));
-assertEquals(123, %ToPrimitive_Number(c));
-
-var d = {
-  [Symbol.toPrimitive]: function(hint) { return hint }
-};
-assertEquals("default", %ToPrimitive(d));
-assertEquals("number", %ToPrimitive_Number(d));
-
-var e = new Date(0);
-assertEquals(e.toString(), %ToPrimitive(e));
-assertEquals(0, %ToPrimitive_Number(e));
diff --git a/implementation-contributed/v8/mjsunit/regress/regress-4271.js b/implementation-contributed/v8/mjsunit/regress/regress-4271.js
index bc18771e72..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/regress-4271.js
+++ b/implementation-contributed/v8/mjsunit/regress/regress-4271.js
@@ -1,24 +0,0 @@
-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-if (this.Worker) {
-  // Throw rather than overflow internal field index
-  assertThrows(function() {
-    Worker.prototype.terminate();
-  });
-
-  assertThrows(function() {
-    Worker.prototype.getMessage();
-  });
-
-  assertThrows(function() {
-    Worker.prototype.postMessage({});
-  });
-
-  // Don't throw for real worker
-  var worker = new Worker('');
-  worker.getMessage();
-  worker.postMessage({});
-  worker.terminate();
-}
diff --git a/implementation-contributed/v8/mjsunit/regress/regress-4279.js b/implementation-contributed/v8/mjsunit/regress/regress-4279.js
index 64ef967d89..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/regress-4279.js
+++ b/implementation-contributed/v8/mjsunit/regress/regress-4279.js
@@ -1,11 +0,0 @@
-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-if (this.Worker && this.quit) {
-  try {
-      new Function(new Worker("55"));
-  } catch(err) {}
-
-  quit();
-}
diff --git a/implementation-contributed/v8/mjsunit/regress/regress-821368.js b/implementation-contributed/v8/mjsunit/regress/regress-821368.js
index b41261d7c9..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/regress-821368.js
+++ b/implementation-contributed/v8/mjsunit/regress/regress-821368.js
@@ -1,14 +0,0 @@
-// Copyright 2018 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-const worker = new Worker("onmessage = function(){}");
-const buffer = new ArrayBuffer();
-worker.postMessage(buffer, [buffer]);
-try {
-  worker.postMessage(buffer, [buffer]);
-} catch (e) {
-  if (e != "ArrayBuffer could not be transferred") {
-    throw e;
-  }
-}
diff --git a/implementation-contributed/v8/mjsunit/regress/regress-crbug-503578.js b/implementation-contributed/v8/mjsunit/regress/regress-crbug-503578.js
index 1274d91ffe..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/regress-crbug-503578.js
+++ b/implementation-contributed/v8/mjsunit/regress/regress-crbug-503578.js
@@ -1,14 +0,0 @@
-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-if (this.Worker) {
-  function __f_0(byteLength) {
-    var __v_1 = new ArrayBuffer(byteLength);
-    var __v_5 = new Uint32Array(__v_1);
-    return __v_5;
-  }
-  var __v_6 = new Worker('onmessage = function() {}');
-  var __v_3 = __f_0(16);
-  __v_6.postMessage(__v_3);
-}
diff --git a/implementation-contributed/v8/mjsunit/regress/regress-crbug-503698.js b/implementation-contributed/v8/mjsunit/regress/regress-crbug-503698.js
index 415d1bc81b..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/regress-crbug-503698.js
+++ b/implementation-contributed/v8/mjsunit/regress/regress-crbug-503698.js
@@ -1,9 +0,0 @@
-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Flags: --invoke-weak-callbacks
-
-if (this.Worker) {
-  var __v_6 = new Worker('');
-}
diff --git a/implementation-contributed/v8/mjsunit/regress/regress-crbug-503968.js b/implementation-contributed/v8/mjsunit/regress/regress-crbug-503968.js
index 78d1c7b98a..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/regress-crbug-503968.js
+++ b/implementation-contributed/v8/mjsunit/regress/regress-crbug-503968.js
@@ -1,13 +0,0 @@
-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-if (this.Worker) {
-  function __f_0() { this.s = new Object(); }
-  function __f_1() {
-    this.l = [new __f_0, new __f_0];
-  }
-  __v_6 = new __f_1;
-  var __v_9 = new Worker('');
-  __v_9.postMessage(__v_6);
-}
diff --git a/implementation-contributed/v8/mjsunit/regress/regress-crbug-503991.js b/implementation-contributed/v8/mjsunit/regress/regress-crbug-503991.js
index 6a3b0de759..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/regress-crbug-503991.js
+++ b/implementation-contributed/v8/mjsunit/regress/regress-crbug-503991.js
@@ -1,9 +0,0 @@
-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-if (this.Worker) {
-  __v_3 = "";
-  var __v_6 = new Worker('');
-  __v_6.postMessage(__v_3);
-}
diff --git a/implementation-contributed/v8/mjsunit/regress/regress-crbug-504136.js b/implementation-contributed/v8/mjsunit/regress/regress-crbug-504136.js
index 4ed6843544..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/regress-crbug-504136.js
+++ b/implementation-contributed/v8/mjsunit/regress/regress-crbug-504136.js
@@ -1,9 +0,0 @@
-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-if (this.Worker) {
-  var __v_10 = new Worker('');
-  __v_10.terminate();
- __v_10.getMessage();
-}
diff --git a/implementation-contributed/v8/mjsunit/regress/regress-crbug-504727.js b/implementation-contributed/v8/mjsunit/regress/regress-crbug-504727.js
index 16d8ff16cd..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/regress-crbug-504727.js
+++ b/implementation-contributed/v8/mjsunit/regress/regress-crbug-504727.js
@@ -1,9 +0,0 @@
-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Flags: --no-test
-
-if (this.Worker) {
-  var __v_2 = new Worker('');
-}
diff --git a/implementation-contributed/v8/mjsunit/regress/regress-crbug-504729.js b/implementation-contributed/v8/mjsunit/regress/regress-crbug-504729.js
index 435cafee87..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/regress-crbug-504729.js
+++ b/implementation-contributed/v8/mjsunit/regress/regress-crbug-504729.js
@@ -1,9 +0,0 @@
-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-if (this.Worker) {
-  Function.prototype.toString = "foo";
-  function __f_7() {}
-  assertThrows(function() { var __v_5 = new Worker(__f_7.toString()); });
-}
diff --git a/implementation-contributed/v8/mjsunit/regress/regress-crbug-505778.js b/implementation-contributed/v8/mjsunit/regress/regress-crbug-505778.js
index 74d96ab094..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/regress-crbug-505778.js
+++ b/implementation-contributed/v8/mjsunit/regress/regress-crbug-505778.js
@@ -1,8 +0,0 @@
-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-if (this.Worker) {
-  var __v_7 = new Worker('onmessage = function() {}');
-  __v_7.postMessage("");
-}
diff --git a/implementation-contributed/v8/mjsunit/regress/regress-crbug-506549.js b/implementation-contributed/v8/mjsunit/regress/regress-crbug-506549.js
index 40e162caf5..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/regress-crbug-506549.js
+++ b/implementation-contributed/v8/mjsunit/regress/regress-crbug-506549.js
@@ -1,10 +0,0 @@
-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-if (this.Worker) {
-  var __v_5 = {};
-  __v_5.__defineGetter__('byteLength', function() {foo();});
-  var __v_8 = new Worker('onmessage = function() {};');
-  assertThrows(function() { __v_8.postMessage(__v_5); });
-}
diff --git a/implementation-contributed/v8/mjsunit/regress/regress-crbug-511880.js b/implementation-contributed/v8/mjsunit/regress/regress-crbug-511880.js
index f9b05ff7bc..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/regress-crbug-511880.js
+++ b/implementation-contributed/v8/mjsunit/regress/regress-crbug-511880.js
@@ -1,13 +0,0 @@
-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-if (this.Worker) {
-  var __v_8 =
-    `var __v_9 = new Worker('postMessage(42)');
-     onmessage = function(parentMsg) {
-       __v_9.postMessage(parentMsg);
-     };`;
-  var __v_9 = new Worker(__v_8);
-  __v_9.postMessage(9);
-}
diff --git a/implementation-contributed/v8/mjsunit/regress/regress-crbug-514081.js b/implementation-contributed/v8/mjsunit/regress/regress-crbug-514081.js
index ee3ed81300..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/regress-crbug-514081.js
+++ b/implementation-contributed/v8/mjsunit/regress/regress-crbug-514081.js
@@ -1,18 +0,0 @@
-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-if (this.Worker) {
-  var __v_7 = new Worker('onmessage = function() {};');
-  var e;
-  var ab = new ArrayBuffer(2 * 1000 * 1000);
-  try {
-    __v_7.postMessage(ab);
-    threw = false;
-  } catch (e) {
-    // postMessage failed, should be a DataCloneError message.
-    assertContains('cloned', e.message);
-    threw = true;
-  }
-  assertTrue(threw, 'Should throw when trying to serialize large message.');
-}
diff --git a/implementation-contributed/v8/mjsunit/regress/regress-crbug-518747.js b/implementation-contributed/v8/mjsunit/regress/regress-crbug-518747.js
index f1787c4c4b..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/regress-crbug-518747.js
+++ b/implementation-contributed/v8/mjsunit/regress/regress-crbug-518747.js
@@ -1,9 +0,0 @@
-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-if (this.Worker) {
-  Worker.prototype = 12;
-  var __v_6 = new Worker('');
-  __v_6.postMessage([]);
-}
diff --git a/implementation-contributed/v8/mjsunit/regress/regress-crbug-522496.js b/implementation-contributed/v8/mjsunit/regress/regress-crbug-522496.js
index e47e0a0677..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/regress-crbug-522496.js
+++ b/implementation-contributed/v8/mjsunit/regress/regress-crbug-522496.js
@@ -1,9 +0,0 @@
-// Copyright 2015 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-if (this.Worker) {
-  var worker = new Worker("onmessage = function(){}");
-  var buf = new ArrayBuffer();
-  worker.postMessage(buf, [buf]);
-}
diff --git a/implementation-contributed/v8/mjsunit/regress/regress-crbug-722871.js b/implementation-contributed/v8/mjsunit/regress/regress-crbug-722871.js
index c5b7958f49..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/regress-crbug-722871.js
+++ b/implementation-contributed/v8/mjsunit/regress/regress-crbug-722871.js
@@ -1,113 +0,0 @@
-// Copyright 2017 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-let sab = new SharedArrayBuffer(10 * 4);
-let memory = new Int32Array(sab);
-let workers = [];
-let runningWorkers = 0;
-
-function startWorker(script) {
-  let worker = new Worker(script);
-  worker.done = false;
-  worker.idx = workers.length;
-  workers.push(worker);
-  worker.postMessage(memory);
-  ++runningWorkers;
-};
-
-let shared = `
-  function wait(memory, index, waitCondition, wakeCondition) {
-    while (memory[index] == waitCondition) {
-      var result = Atomics.wait(memory, index, waitCondition);
-      switch (result) {
-        case 'not-equal':
-        case 'ok':
-          break;
-        default:
-          postMessage('Error: bad result from wait: ' + result);
-          break;
-      }
-      var value = memory[index];
-      if (value != wakeCondition) {
-        postMessage(
-            'Error: wait returned not-equal but the memory has a bad value: ' +
-            value);
-      }
-    }
-    var value = memory[index];
-    if (value != wakeCondition) {
-      postMessage(
-          'Error: done waiting but the memory has a bad value: ' + value);
-    }
-  }
-
-  function wake(memory, index) {
-    var result = Atomics.wake(memory, index, 1);
-    if (result != 0 && result != 1) {
-      postMessage('Error: bad result from wake: ' + result);
-    }
-  }
-`;
-
-let worker1 = startWorker(shared + `
-  onmessage = function(msg) {
-    let memory = msg;
-    const didStartIdx = 0;
-    const shouldGoIdx = 1;
-    const didEndIdx = 2;
-
-    postMessage("started");
-    postMessage("memory: " + memory);
-    wait(memory, didStartIdx, 0, 1);
-    memory[shouldGoIdx] = 1;
-    wake(memory, shouldGoIdx);
-    wait(memory, didEndIdx, 0, 1);
-    postMessage("memory: " + memory);
-    postMessage("done");
-  };
-`);
-
-let worker2 = startWorker(shared + `
-  onmessage = function(msg) {
-    let memory = msg;
-    const didStartIdx = 0;
-    const shouldGoIdx = 1;
-    const didEndIdx = 2;
-
-    postMessage("started");
-    postMessage("memory: " + memory);
-    Atomics.store(memory, didStartIdx, 1);
-    wake(memory, didStartIdx);
-    wait(memory, shouldGoIdx, 0, 1);
-    Atomics.store(memory, didEndIdx, 1);
-    wake(memory, didEndIdx, 1);
-    postMessage("memory: " + memory);
-    postMessage("done");
-  };
-`);
-
-let running = true;
-while (running) {
-  for (let worker of workers) {
-    if (worker.done) continue;
-
-    let msg = worker.getMessage();
-    if (msg) {
-      switch (msg) {
-        case "done":
-          if (worker.done === false) {
-            print("worker #" + worker.idx + " done.");
-            worker.done = true;
-            if (--runningWorkers === 0) {
-              running = false;
-            }
-          }
-          break;
-
-        default:
-          print("msg from worker #" + worker.idx + ": " + msg);
-          break;
-      }
-    }
-  }
-}
diff --git a/implementation-contributed/v8/mjsunit/regress/wasm/regress-801850.js b/implementation-contributed/v8/mjsunit/regress/wasm/regress-801850.js
index ad6ff4c432..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/wasm/regress-801850.js
+++ b/implementation-contributed/v8/mjsunit/regress/wasm/regress-801850.js
@@ -1,11 +0,0 @@
-// Copyright 2018 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-load('test/mjsunit/wasm/wasm-constants.js');
-load('test/mjsunit/wasm/wasm-module-builder.js');
-
-var builder = new WasmModuleBuilder();
-let module = new WebAssembly.Module(builder.toBuffer());
-var worker = new Worker('onmessage = function() {};');
-worker.postMessage(module)
diff --git a/implementation-contributed/v8/mjsunit/regress/wasm/regress-803427.js b/implementation-contributed/v8/mjsunit/regress/wasm/regress-803427.js
index 833b140fd4..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/wasm/regress-803427.js
+++ b/implementation-contributed/v8/mjsunit/regress/wasm/regress-803427.js
@@ -1,13 +0,0 @@
-// Copyright 2018 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Flags: --wasm-lazy-compilation
-
-load('test/mjsunit/wasm/wasm-constants.js');
-load('test/mjsunit/wasm/wasm-module-builder.js');
-
-var builder = new WasmModuleBuilder();
-let module = new WebAssembly.Module(builder.toBuffer());
-var worker = new Worker('onmessage = function() {};');
-worker.postMessage(module)
diff --git a/implementation-contributed/v8/mjsunit/regress/wasm/regress-8059.js b/implementation-contributed/v8/mjsunit/regress/wasm/regress-8059.js
index 5c421c4ee4..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/wasm/regress-8059.js
+++ b/implementation-contributed/v8/mjsunit/regress/wasm/regress-8059.js
@@ -1,42 +0,0 @@
-// Copyright 2018 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Flags: --no-wasm-disable-structured-cloning
-
-load("test/mjsunit/wasm/wasm-constants.js");
-load("test/mjsunit/wasm/wasm-module-builder.js");
-
-(function TestPostModule() {
-  let builder = new WasmModuleBuilder();
-  builder.addFunction("add", kSig_i_ii)
-    .addBody([kExprGetLocal, 0, kExprGetLocal, 1, kExprI32Add])
-    .exportFunc();
-
-  let module = builder.toModule();
-
-  let workerScript = `
-    onmessage = function(module) {
-      try {
-        let instance = new WebAssembly.Instance(module);
-        let result = instance.exports.add(40, 2);
-        postMessage(result);
-      } catch(e) {
-        postMessage('ERROR: ' + e);
-      }
-    }
-  `;
-
-  let realm = Realm.create();
-  Realm.shared = { m:module, s:workerScript };
-
-  let realmScript = `
-    let worker = new Worker(Realm.shared.s);
-    worker.postMessage(Realm.shared.m);
-    let message = worker.getMessage();
-    worker.terminate();
-    message;
-  `;
-  let message = Realm.eval(realm, realmScript);
-  assertEquals(42, message);
-})();
diff --git a/implementation-contributed/v8/mjsunit/regress/wasm/regress-808012.js b/implementation-contributed/v8/mjsunit/regress/wasm/regress-808012.js
index 1b91f226a8..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/wasm/regress-808012.js
+++ b/implementation-contributed/v8/mjsunit/regress/wasm/regress-808012.js
@@ -1,14 +0,0 @@
-// Copyright 2018 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Flags: --wasm-lazy-compilation
-
-load('test/mjsunit/wasm/wasm-constants.js');
-load('test/mjsunit/wasm/wasm-module-builder.js');
-
-const builder = new WasmModuleBuilder();
-builder.addFunction('test', kSig_i_i).addBody([kExprUnreachable]);
-let module = new WebAssembly.Module(builder.toBuffer());
-var worker = new Worker('onmessage = function() {};');
-worker.postMessage(module);
diff --git a/implementation-contributed/v8/mjsunit/regress/wasm/regress-808848.js b/implementation-contributed/v8/mjsunit/regress/wasm/regress-808848.js
index 69423b954d..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/regress/wasm/regress-808848.js
+++ b/implementation-contributed/v8/mjsunit/regress/wasm/regress-808848.js
@@ -1,67 +0,0 @@
-// Copyright 2018 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Flags: --allow-natives-syntax
-
-load('test/mjsunit/wasm/wasm-constants.js');
-load('test/mjsunit/wasm/wasm-module-builder.js');
-
-// The number of locals must be greater than the constant defined here:
-// https://cs.chromium.org/chromium/src/v8/src/compiler/x64/code-generator-x64.cc?l=3146
-const kNumLocals = 128;
-
-function varuint32(val) {
-  let bytes = [];
-  for (let i = 0; i < 4; ++i) {
-    bytes.push(0x80 | ((val >> (7 * i)) & 0x7f));
-  }
-  bytes.push((val >> (7 * 4)) & 0x7f);
-  return bytes;
-}
-
-// Generate a function that calls the "get" import `kNumLocals` times, and
-// stores each result in a local, then calls the "call" import `kNumLocals`
-// times with the stored local values.
-//
-// The intention is to create a function that has a large stack frame.
-let body = [];
-
-for (let i = 0; i < kNumLocals; ++i) {
-  body.push(kExprCallFunction, 0, kExprSetLocal, ...varuint32(i));
-}
-
-for (let i = 0; i < kNumLocals; ++i) {
-  body.push(kExprGetLocal, ...varuint32(i), kExprCallFunction, 1);
-}
-
-let builder = new WasmModuleBuilder();
-builder.addImport('mod', 'get', kSig_i_v);
-builder.addImport('mod', 'call', kSig_v_i);
-builder.
-  addFunction('main', kSig_v_v).
-  addLocals({i32_count: kNumLocals}).
-  addBody(body).
-  exportAs('main');
-let m1_bytes = builder.toBuffer();
-let m1 = new WebAssembly.Module(m1_bytes);
-
-// Serialize the module and postMessage it to another thread.
-let serialized_m1 = %SerializeWasmModule(m1);
-
-let worker_onmessage = function(msg) {
-  let {serialized_m1, m1_bytes} = msg;
-
-  let m1_clone = %DeserializeWasmModule(serialized_m1, m1_bytes);
-  let imports = {mod: {get: () => 3, call: () => {}}};
-  let i2 = new WebAssembly.Instance(m1_clone, imports);
-  i2.exports.main();
-  postMessage('done');
-}
-let workerScript = "onmessage = " + worker_onmessage.toString();
-
-let worker = new Worker(workerScript);
-worker.postMessage({serialized_m1, m1_bytes});
-
-// Wait for worker to finish.
-print(worker.getMessage());
diff --git a/implementation-contributed/v8/mjsunit/samevalue.js b/implementation-contributed/v8/mjsunit/samevalue.js
index 356e888016..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/samevalue.js
+++ b/implementation-contributed/v8/mjsunit/samevalue.js
@@ -1,120 +0,0 @@
-// Copyright 2010 the V8 project authors. All rights reserved.
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-//       notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-//       copyright notice, this list of conditions and the following
-//       disclaimer in the documentation and/or other materials provided
-//       with the distribution.
-//     * Neither the name of Google Inc. nor the names of its
-//       contributors may be used to endorse or promote products derived
-//       from this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-
-// Flags: --expose-natives-as natives --allow-natives-syntax
-// Test the SameValue and SameValueZero internal methods.
-
-var obj1 = {x: 10, y: 11, z: "test"};
-var obj2 = {x: 10, y: 11, z: "test"};
-
-var sameValue = Object.is;
-var sameValueZero = function(x, y) { return %SameValueZero(x, y); }
-
-// Calls SameValue and SameValueZero and checks that their results match.
-function sameValueBoth(a, b) {
-  var result = sameValue(a, b);
-  assertTrue(result === sameValueZero(a, b));
-  return result;
-}
-
-// Calls SameValue and SameValueZero and checks that their results don't match.
-function sameValueZeroOnly(a, b) {
-  var result = sameValueZero(a, b);
-  assertTrue(result && !sameValue(a, b));
-  return result;
-}
-
-assertTrue(sameValueBoth(0, 0));
-assertTrue(sameValueBoth(+0, +0));
-assertTrue(sameValueBoth(-0, -0));
-assertTrue(sameValueBoth(1, 1));
-assertTrue(sameValueBoth(2, 2));
-assertTrue(sameValueBoth(-1, -1));
-assertTrue(sameValueBoth(0.5, 0.5));
-assertTrue(sameValueBoth(true, true));
-assertTrue(sameValueBoth(false, false));
-assertTrue(sameValueBoth(NaN, NaN));
-assertTrue(sameValueBoth(null, null));
-assertTrue(sameValueBoth("foo", "foo"));
-assertTrue(sameValueBoth(obj1, obj1));
-// Undefined values.
-assertTrue(sameValueBoth());
-assertTrue(sameValueBoth(undefined, undefined));
-
-assertFalse(sameValueBoth(0,1));
-assertFalse(sameValueBoth("foo", "bar"));
-assertFalse(sameValueBoth(obj1, obj2));
-assertFalse(sameValueBoth(true, false));
-
-assertFalse(sameValueBoth(obj1, true));
-assertFalse(sameValueBoth(obj1, "foo"));
-assertFalse(sameValueBoth(obj1, 1));
-assertFalse(sameValueBoth(obj1, undefined));
-assertFalse(sameValueBoth(obj1, NaN));
-
-assertFalse(sameValueBoth(undefined, true));
-assertFalse(sameValueBoth(undefined, "foo"));
-assertFalse(sameValueBoth(undefined, 1));
-assertFalse(sameValueBoth(undefined, obj1));
-assertFalse(sameValueBoth(undefined, NaN));
-
-assertFalse(sameValueBoth(NaN, true));
-assertFalse(sameValueBoth(NaN, "foo"));
-assertFalse(sameValueBoth(NaN, 1));
-assertFalse(sameValueBoth(NaN, obj1));
-assertFalse(sameValueBoth(NaN, undefined));
-
-assertFalse(sameValueBoth("foo", true));
-assertFalse(sameValueBoth("foo", 1));
-assertFalse(sameValueBoth("foo", obj1));
-assertFalse(sameValueBoth("foo", undefined));
-assertFalse(sameValueBoth("foo", NaN));
-
-assertFalse(sameValueBoth(true, 1));
-assertFalse(sameValueBoth(true, obj1));
-assertFalse(sameValueBoth(true, undefined));
-assertFalse(sameValueBoth(true, NaN));
-assertFalse(sameValueBoth(true, "foo"));
-
-assertFalse(sameValueBoth(1, true));
-assertFalse(sameValueBoth(1, obj1));
-assertFalse(sameValueBoth(1, undefined));
-assertFalse(sameValueBoth(1, NaN));
-assertFalse(sameValueBoth(1, "foo"));
-
-// Special string cases.
-assertFalse(sameValueBoth("1", 1));
-assertFalse(sameValueBoth("true", true));
-assertFalse(sameValueBoth("false", false));
-assertFalse(sameValueBoth("undefined", undefined));
-assertFalse(sameValueBoth("NaN", NaN));
-
-// SameValue considers -0 and +0 to be different; SameValueZero considers
-// -0 and +0 to be the same.
-assertTrue(sameValueZeroOnly(+0, -0));
-assertTrue(sameValueZeroOnly(-0, +0));
diff --git a/implementation-contributed/v8/mjsunit/test-async.js b/implementation-contributed/v8/mjsunit/test-async.js
index f8a11c5238..e69de29bb2 100644
--- a/implementation-contributed/v8/mjsunit/test-async.js
+++ b/implementation-contributed/v8/mjsunit/test-async.js
@@ -1,117 +0,0 @@
-// Copyright 2018 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Flags: --allow-natives-syntax
-
-// Used for async tests. See definition below for more documentation.
-var testAsync;
-
-(function () {  // Scope for utility functions.
-  /**
-   * This is to be used through the testAsync helper function defined
-   * below.
-   *
-   * This requires the --allow-natives-syntax flag to allow calling
-   * runtime functions.
-   *
-   * There must be at least one assertion in an async test. A test
-   * with no assertions will fail.
-   *
-   * @example
-   * testAsync(assert => {
-   *   assert.plan(1) // There should be one assertion in this test.
-   *   Promise.resolve(1)
-   *    .then(val => assert.equals(1, val),
-   *          assert.unreachable);
-   * })
-   */
-  class AsyncAssertion {
-    constructor(test, name) {
-      this.expectedAsserts_ = -1;
-      this.actualAsserts_ = 0;
-      this.test_ = test;
-      this.name_ = name || '';
-    }
-
-    /**
-     * Sets the number of expected asserts in the test. The test fails
-     * if the number of asserts computed after running the test is not
-     * equal to this specified value.
-     * @param {number} expectedAsserts
-     */
-    plan(expectedAsserts) {
-      this.expectedAsserts_ = expectedAsserts;
-    }
-
-    fail(expectedText, found) {
-      let message = formatFailureText(expectedText, found);
-      message += "\nin test:" + this.name_
-      message += "\n" + Function.prototype.toString.apply(this.test_);
-      %AbortJS(message);
-    }
-
-    equals(expected, found, name_opt) {
-      this.actualAsserts_++;
-      if (expected !== found) {
-        this.fail(prettyPrinted(expected), found, name_opt);
-      }
-    }
-
-    unreachable() {
-      let message = "Failure: unreachable in test: " + this.name_;
-      message += "\n" + Function.prototype.toString.apply(this.test_);
-      %AbortJS(message);
-    }
-
-    unexpectedRejection(details) {
-      return (error) => {
-        let message =
-            "Failure: unexpected Promise rejection in test: " + this.name_;
-        if (details) message += "\n    @" + details;
-        if (error instanceof Error) {
-          message += "\n" + String(error.stack);
-        } else {
-          message += "\n" + String(error);
-        }
-        message += "\n\n" + Function.prototype.toString.apply(this.test_);
-        %AbortJS(message);
-      };
-    }
-
-    drainMicrotasks() {
-      %RunMicrotasks();
-    }
-
-    done_() {
-      if (this.expectedAsserts_ === -1) {
-        let message = "Please call t.plan(count) to initialize test harness " +
-            "with correct assert count (Note: count > 0)";
-        %AbortJS(message);
-      }
-
-      if (this.expectedAsserts_ !== this.actualAsserts_) {
-        let message = "Expected asserts: " + this.expectedAsserts_;
-        message += ", Actual asserts: " + this.actualAsserts_;
-        message += "\nin test: " + this.name_;
-        message += "\n" + Function.prototype.toString.apply(this.test_);
-        %AbortJS(message);
-      }
-    }
-  }
-
-  /** This is used to test async functions and promises.
-   * @param {testCallback} test - test function
-   * @param {string} [name] - optional name of the test
-   *
-   *
-   * @callback testCallback
-   * @param {AsyncAssertion} assert
-   */
-  testAsync = function(test, name) {
-    let assert = new AsyncAssertion(test, name);
-    test(assert);
-    %RunMicrotasks();
-    assert.done_();
-  }
-})();
diff --git a/implementation-contributed/v8/test262/harness-agent.js b/implementation-contributed/v8/test262/harness-agent.js
index 83f688cf07..e69de29bb2 100644
--- a/implementation-contributed/v8/test262/harness-agent.js
+++ b/implementation-contributed/v8/test262/harness-agent.js
@@ -1,118 +0,0 @@
-// Copyright 2017 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-$262.agent = (function () {
-
-var workers = [];
-var i32a = null;
-var pendingReports = [];
-
-// Agents call Atomics.wait on this location to sleep.
-var SLEEP_LOC = 0;
-// 1 if the started worker is ready, 0 otherwise.
-var START_LOC = 1;
-// The number of workers that have received the broadcast.
-var BROADCAST_LOC = 2;
-// Each worker has a count of outstanding reports; worker N uses memory
-// location [WORKER_REPORT_LOC + N].
-var WORKER_REPORT_LOC = 3;
-
-function workerScript(script) {
-  return `
-    var index;
-    var i32a = null;
-    var broadcasts = [];
-    var pendingReceiver = null;
-
-    function handleBroadcast() {
-      if (pendingReceiver && broadcasts.length > 0) {
-        pendingReceiver.apply(null, broadcasts.shift());
-        pendingReceiver = null;
-      }
-    };
-
-    var onmessage = function(msg) {
-      switch (msg.kind) {
-        case 'start':
-          i32a = msg.i32a;
-          index = msg.index;
-          (0, eval)(\`${script}\`);
-          break;
-
-        case 'broadcast':
-          Atomics.add(i32a, ${BROADCAST_LOC}, 1);
-          broadcasts.push([msg.sab, msg.id]);
-          handleBroadcast();
-          break;
-      }
-    };
-
-    var $262 = {
-      agent: {
-        receiveBroadcast(receiver) {
-          pendingReceiver = receiver;
-          handleBroadcast();
-        },
-
-        report(msg) {
-          postMessage(String(msg));
-          Atomics.add(i32a, ${WORKER_REPORT_LOC} + index, 1);
-        },
-
-        sleep(s) { Atomics.wait(i32a, ${SLEEP_LOC}, 0, s); },
-
-        leaving() {},
-
-        monotonicNow() {
-          return performance.now();
-        }
-      }
-    };`;
-}
-
-var agent = {
-  start(script) {
-    if (i32a === null) {
-      i32a = new Int32Array(new SharedArrayBuffer(256));
-    }
-    var w = new Worker(workerScript(script));
-    w.index = workers.length;
-    w.postMessage({kind: 'start', i32a: i32a, index: w.index});
-    workers.push(w);
-  },
-
-  broadcast(sab, id) {
-    if (!(sab instanceof SharedArrayBuffer)) {
-      throw new TypeError('sab must be a SharedArrayBuffer.');
-    }
-
-    Atomics.store(i32a, BROADCAST_LOC, 0);
-
-    for (var w of workers) {
-      w.postMessage({kind: 'broadcast', sab: sab, id: id|0});
-    }
-
-    while (Atomics.load(i32a, BROADCAST_LOC) != workers.length) {}
-  },
-
-  getReport() {
-    for (var w of workers) {
-      while (Atomics.load(i32a, WORKER_REPORT_LOC + w.index) > 0) {
-        pendingReports.push(w.getMessage());
-        Atomics.sub(i32a, WORKER_REPORT_LOC + w.index, 1);
-      }
-    }
-
-    return pendingReports.shift() || null;
-  },
-
-  sleep(s) { Atomics.wait(i32a, SLEEP_LOC, 0, s); },
-
-  monotonicNow() {
-    return performance.now();
-  }
-};
-return agent;
-
-})();