Wrap harmony implementations in functions.

src/harmony-array-includes.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.
 
+(function() {
+
 'use strict';
 
-// This file relies on the fact that the following declaration has been made
-// in runtime.js:
-// var $Array = global.Array;
+%CheckIsBootstrapping();
+
+var GlobalArray = global.Array;
 
 // -------------------------------------------------------------------
 
 // Proposed for ES7
 // https://github.com/tc39/Array.prototype.includes
 // 6e3b78c927aeda20b9d40e81303f9d44596cd904
 function ArrayIncludes(searchElement, fromIndex) {
   var array = ToObject(this);
   var len = ToLength(array.length);
 
@@ skipping 20 matching lines @@
     }
 
     ++k;
   }
 
   return false;
 }
 
 // -------------------------------------------------------------------
 
-function HarmonyArrayIncludesExtendArrayPrototype() {
-  %CheckIsBootstrapping();
+%FunctionSetLength(ArrayIncludes, 1);
 
-  %FunctionSetLength(ArrayIncludes, 1);
+// Set up the non-enumerable functions on the Array prototype object.
+InstallFunctions(GlobalArray.prototype, DONT_ENUM, [
+  "includes", ArrayIncludes
+]);
 
-  // Set up the non-enumerable functions on the Array prototype object.
-  InstallFunctions($Array.prototype, DONT_ENUM, [
-    "includes", ArrayIncludes
-  ]);
-}
-
-HarmonyArrayIncludesExtendArrayPrototype();
+})();