[es6] implement Object.assign

src/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.
 
 // This file relies on the fact that the following declarations have been made
 // in runtime.js:
 // var $Object = global.Object;
 // var $Boolean = global.Boolean;
 // var $Number = global.Number;
 // var $Function = global.Function;
@@ skipping 241 matching lines @@
 
 // ECMA-262 - 15.2.4.6
 function ObjectIsPrototypeOf(V) {
   if (!IS_SPEC_OBJECT(V)) return false;
   CHECK_OBJECT_COERCIBLE(this, "Object.prototype.isPrototypeOf");
   return %IsInPrototypeChain(this, V);
 }
 
 
 // ECMA-262 - 15.2.4.6
-function ObjectPropertyIsEnumerable(V) {
+function ObjectPropertyIsEnumerableJS(O, V) {
   var P = ToName(V);
-  if (%_IsJSProxy(this)) {
+  if (%_IsJSProxy(O)) {
     // TODO(rossberg): adjust once there is a story for symbols vs proxies.
     if (IS_SYMBOL(V)) return false;
 
-    var desc = GetOwnPropertyJS(this, P);
+    var desc = GetOwnPropertyJS(O, P);
     return IS_UNDEFINED(desc) ? false : desc.isEnumerable();
   }
-  return %IsPropertyEnumerable(ToObject(this), P);
+  return %IsPropertyEnumerable(ToObject(O), P);
 }
 
 
+function ObjectPropertyIsEnumerable(V) {
+  return ObjectPropertyIsEnumerableJS(this, V);
+}
+
+
 // Extensions for providing property getters and setters.
 function ObjectDefineGetter(name, fun) {
   var receiver = this;
   if (receiver == null && !IS_UNDETECTABLE(receiver)) {
     receiver = %GlobalProxy(global);
   }
   if (!IS_SPEC_FUNCTION(fun)) {
     throw new $TypeError(
         'Object.prototype.__defineGetter__: Expecting function');
   }
@@ skipping 1615 matching lines @@
   }
   if (!IS_SPEC_FUNCTION(method)) {
     throw MakeTypeError('not_iterable', [obj]);
   }
   var iterator = %_CallFunction(obj, method);
   if (!IS_SPEC_OBJECT(iterator)) {
     throw MakeTypeError('not_an_iterator', [iterator]);
   }
   return iterator;
 }