[stubs] Unify (and optimize) implementation of ToObject.

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(global, utils) {
 
 'use strict';
 
 %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 array = TO_OBJECT(this);
   var len = $toLength(array.length);
 
   if (len === 0) {
     return false;
   }
 
   var n = $toInteger(fromIndex);
 
   var k;
   if (n >= 0) {
@@ skipping 20 matching lines @@
 // -------------------------------------------------------------------
 
 %FunctionSetLength(ArrayIncludes, 1);
 
 // Set up the non-enumerable functions on the Array prototype object.
 utils.InstallFunctions(GlobalArray.prototype, DONT_ENUM, [
   "includes", ArrayIncludes
 ]);
 
 })