Fix issue with __proto__ when using ES6 object literals

test/mjsunit/harmony/object-literals-property-shorthand.js

 // Copyright 2014 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: --harmony-object-literals
 
 
 (function TestBasics() {
   var x = 1;
   var object = {x};
@@ skipping 31 matching lines @@
   var yield = 1;
   var object = {yield};
   assertEquals(1, object.yield);
 })();
 
 
 (function TestToString() {
   function f(x) { return {x}; }
   assertEquals('function f(x) { return {x}; }', f.toString());
 })();
+
+
+(function TestProtoName() {
+  var __proto__ = 1;
+  var object = {
+    __proto__
+  };
+  assertEquals(Object.prototype, Object.getPrototypeOf(object));
+  assertEquals(1, object.__proto__);
+})();
+
+
+(function TestProtoName2() {
+  var __proto__ = 1;
+  var p = {};
+  var object = {
+    __proto__: p,
+    __proto__,
+  };
+  assertEquals(p, Object.getPrototypeOf(object));
+  assertEquals(1, object.__proto__);
+})();