Revert of [builtins] Also port the Object.prototype.__proto__ accessors to C++.

src/js/v8natives.js

 // Copyright 2012 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.
 
 (function(global, utils) {
 
 %CheckIsBootstrapping();
 
 // ----------------------------------------------------------------------------
 // Imports
@@ skipping 86 matching lines @@
 
 
 // ES6 7.3.9
 function GetMethod(obj, p) {
   var func = obj[p];
   if (IS_NULL_OR_UNDEFINED(func)) return UNDEFINED;
   if (IS_CALLABLE(func)) return func;
   throw %make_type_error(kCalledNonCallable, typeof func);
 }
 
+// ES6 B.2.2.1.1
+function ObjectGetProto() {
+  return %object_get_prototype_of(this);
+}
+
+
+// ES6 B.2.2.1.2
+function ObjectSetProto(proto) {
+  CHECK_OBJECT_COERCIBLE(this, "Object.prototype.__proto__");
+
+  if ((IS_RECEIVER(proto) || IS_NULL(proto)) && IS_RECEIVER(this)) {
+    %SetPrototype(this, proto);
+  }
+}
+
+
 // ES6 19.1.1.1
 function ObjectConstructor(x) {
   if (GlobalObject != new.target && !IS_UNDEFINED(new.target)) {
     return this;
   }
   if (IS_NULL(x) || IS_UNDEFINED(x)) return {};
   return TO_OBJECT(x);
 }
 
 
@@ skipping 11 matching lines @@
   "toString", ObjectToString,
   "toLocaleString", ObjectToLocaleString,
   "valueOf", ObjectValueOf,
   "isPrototypeOf", ObjectIsPrototypeOf,
   // propertyIsEnumerable is added in bootstrapper.cc.
   // __defineGetter__ is added in bootstrapper.cc.
   // __lookupGetter__ is added in bootstrapper.cc.
   // __defineSetter__ is added in bootstrapper.cc.
   // __lookupSetter__ is added in bootstrapper.cc.
 ]);
+utils.InstallGetterSetter(
+    GlobalObject.prototype, "__proto__", ObjectGetProto, ObjectSetProto);
 
 
 // ----------------------------------------------------------------------------
 // Number
 
 utils.InstallConstants(GlobalNumber, [
   // ECMA-262 section 15.7.3.1.
   "MAX_VALUE", 1.7976931348623157e+308,
   // ECMA-262 section 15.7.3.2.
   "MIN_VALUE", 5e-324,
@@ skipping 43 matching lines @@
   to.GetIterator = GetIterator;
   to.GetMethod = GetMethod;
   to.ObjectHasOwnProperty = GlobalObject.prototype.hasOwnProperty;
 });
 
 %InstallToContext([
   "object_value_of", ObjectValueOf,
 ]);
 
 })