Install iterator meta objects via utils object.

src/js/iterator-prototype.js

 // Copyright 2015 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.
 
-var $iteratorPrototype;
-
 (function(global, utils) {
   "use strict";
   %CheckIsBootstrapping();
 
   var GlobalObject = global.Object;
+  var IteratorPrototype = utils.ImportNow("IteratorPrototype");
   var iteratorSymbol = utils.ImportNow("iterator_symbol");
 
   // 25.1.2.1 %IteratorPrototype% [ @@iterator ] ( )
   function IteratorPrototypeIterator() {
     return this;
   }
 
   utils.SetFunctionName(IteratorPrototypeIterator, iteratorSymbol);
-  %AddNamedProperty($iteratorPrototype, iteratorSymbol,
+  %AddNamedProperty(IteratorPrototype, iteratorSymbol,
       IteratorPrototypeIterator, DONT_ENUM);
 })