Bring back accidentally removed __proto__ test

test/annexB/built-ins/Proxy/set/call-parameters-prototype-dunder-proto.js

@@ -0,0 +1,56 @@
+// Copyright (C) 2019 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-proxy-object-internal-methods-and-internal-slots-set-p-v-receiver
+description: >
+  Ordinary [[Set]] forwards call to Proxy "set" trap with correct arguments.
+  Property name is "__proto__".
+info: |
+  OrdinarySet ( O, P, V, Receiver )
+
+  ...
+  3. Return OrdinarySetWithOwnDescriptor(O, P, V, Receiver, ownDesc).
+
+  OrdinarySetWithOwnDescriptor ( O, P, V, Receiver, ownDesc )
+
+  ...
+  2. If ownDesc is undefined, then
+    a. Let parent be ? O.[[GetPrototypeOf]]().
+    b. If parent is not null, then
+      i. Return ? parent.[[Set]](P, V, Receiver).
+
+  [[Set]] ( P, V, Receiver )
+
+  ...
+  8. Let booleanTrapResult be ! ToBoolean(? Call(trap, handler, « target, P, V, Receiver »)).
+  ...
+  12. Return true.
+includes: [proxyTrapsHelper.js]
+features: [Proxy]
+---*/
+
+var _handler, _target, _prop, _value, _receiver;
+var target = {};
+var handler = allowProxyTraps({
+  set: function(target, prop, value, receiver) {
+    _handler = this;
+    _target = target;
+    _prop = prop;
+    _value = value;
+    _receiver = receiver;
+    return true;
+  },
+});
+
+var proxy = new Proxy(target, handler);
+var receiver = Object.create(proxy);
+var prop = '__proto__';
+var value = {};
+
+receiver[prop] = value;
+
+assert.sameValue(_handler, handler, 'handler object is the trap context');
+assert.sameValue(_target, target, 'first argument is the target object');
+assert.sameValue(_prop, prop, 'second argument is the property name');
+assert.sameValue(_value, value, 'third argument is the new value');
+assert.sameValue(_receiver, receiver, 'fourth argument is the receiver object');