Add shift to InternalArray and InternalPackedArray

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.
 
 var $arrayConcat;
 var $arrayJoin;
 var $arrayPush;
 var $arrayPop;
 var $arrayShift;
 var $arraySlice;
@@ skipping 1561 matching lines @@
 
 // The internal Array prototype doesn't need to be fancy, since it's never
 // exposed to user code.
 // Adding only the functions that are actually used.
 SetUpLockedPrototype(InternalArray, GlobalArray(), [
   "concat", getFunction("concat", ArrayConcatJS),
   "indexOf", getFunction("indexOf", ArrayIndexOf),
   "join", getFunction("join", ArrayJoin),
   "pop", getFunction("pop", ArrayPop),
   "push", getFunction("push", ArrayPush),
+  "shift", getFunction("shift", ArrayShift),
   "splice", getFunction("splice", ArraySplice)
 ]);
 
 SetUpLockedPrototype(InternalPackedArray, GlobalArray(), [
   "join", getFunction("join", ArrayJoin),
   "pop", getFunction("pop", ArrayPop),
-  "push", getFunction("push", ArrayPush)
+  "push", getFunction("push", ArrayPush),
+  "shift", getFunction("shift", ArrayShift)
 ]);
 
 $arrayConcat = ArrayConcatJS;
 $arrayJoin = ArrayJoin;
 $arrayPush = ArrayPush;
 $arrayPop = ArrayPop;
 $arrayShift = ArrayShift;
 $arraySlice = ArraySlice;
 $arraySplice = ArraySplice;
 $arrayUnshift = ArrayUnshift;
 
 })();