Use simple keyed store again in ArrayPush_JS_Builtin

src/array.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.
 
 "use strict";
 
 // This file relies on the fact that the following declarations have been made
 // in runtime.js:
 // var $Array = global.Array;
 
@@ skipping 425 matching lines @@
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.push");
 
   if (%IsObserved(this))
     return ObservedArrayPush.apply(this, arguments);
 
   var array = TO_OBJECT_INLINE(this);
   var n = TO_UINT32(array.length);
   var m = %_ArgumentsLength();
 
   for (var i = 0; i < m; i++) {
-    // Use SetProperty rather than a direct keyed store to ensure that the store
-    // site doesn't become poisened with an elements transition KeyedStoreIC.
-    %SetProperty(array, i+n, %_Arguments(i), 0, kStrictMode);
+    array[i+n] = %_Arguments(i);
   }
 
   var new_length = n + m;
   array.length = new_length;
   return new_length;
 }
 
 
 // Returns an array containing the array elements of the object followed
 // by the array elements of each argument in order. See ECMA-262,
@@ skipping 1066 matching lines @@
   ));
 
   SetUpLockedPrototype(InternalPackedArray, $Array(), $Array(
     "join", getFunction("join", ArrayJoin),
     "pop", getFunction("pop", ArrayPop),
     "push", getFunction("push", ArrayPush)
   ));
 }
 
 SetUpArray();