Add tests for accessors setting precedessors

test/built-ins/Array/prototype/sort/precise-getter-sets-predecessor.js

@@ -0,0 +1,41 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-array.prototype.sort
+description: >
+  Previously implementation-defined aspects of Array.prototype.sort.
+info: |
+  Historically, many aspects of Array.prototype.sort remained
+  implementation-defined. https://github.com/tc39/ecma262/pull/1585
+  described some behaviors more precisely, reducing the amount of cases
+  that result in an implementation-defined sort order.
+---*/
+
+const array = [undefined, 'c', /*hole*/, 'b', undefined, /*hole*/, 'a', 'd'];
+
+Object.defineProperty(array, '2', {
+  get() {
+    array[1] = 'foobar';
+    return this.foo;
+  },
+  set(v) {
+    this.foo = v;
+  }
+});
+
+array.sort();
+
+assert.sameValue(array[0], 'a');
+assert.sameValue(array[1], 'b');
+assert.sameValue(array[3], 'd');
+assert.sameValue(array[4], undefined);
+assert.sameValue(array[5], undefined);
+assert.sameValue(array[6], undefined);
+assert.sameValue('7' in array, false);
+assert.sameValue(array.hasOwnProperty('7'), false);
+assert.sameValue(array.length, 8);
+assert.sameValue(array.foo, 'c');
+
+assert.sameValue(array[2], 'c');
+assert.sameValue(array[1], 'foobar');

test/built-ins/Array/prototype/sort/precise-setter-sets-predecessor.js

@@ -0,0 +1,39 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-array.prototype.sort
+description: >
+  Previously implementation-defined aspects of Array.prototype.sort.
+info: |
+  Historically, many aspects of Array.prototype.sort remained
+  implementation-defined. https://github.com/tc39/ecma262/pull/1585
+  described some behaviors more precisely, reducing the amount of cases
+  that result in an implementation-defined sort order.
+---*/
+
+const array = [undefined, 'c', /*hole*/, 'b', undefined, /*hole*/, 'a', 'd'];
+
+Object.defineProperty(array, '2', {
+  get() {
+    return this.foo;
+  },
+  set(v) {
+    array[1] = 'foobar';
+    this.foo = v;
+  }
+});
+
+array.sort();
+
+assert.sameValue(array[0], 'a');
+assert.sameValue(array[1], 'foobar');
+assert.sameValue(array[2], 'c');
+assert.sameValue(array[3], 'd');
+assert.sameValue(array[4], undefined);
+assert.sameValue(array[5], undefined);
+assert.sameValue(array[6], undefined);
+assert.sameValue('7' in array, false);
+assert.sameValue(array.hasOwnProperty('7'), false);
+assert.sameValue(array.length, 8);
+assert.sameValue(array.foo, 'c');