Remove hand-written assembly ArrayPush stubs

src/array.js

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 452 matching lines @@
   var m = %_ArgumentsLength();
   if (m > 0 && ObjectIsSealed(this)) {
     throw MakeTypeError("array_functions_change_sealed",
                         ["Array.prototype.push"]);
   }
 
   if (%IsObserved(this))
     return ObservedArrayPush.apply(this, arguments);
 
   for (var i = 0; i < m; i++) {
-    this[i+n] = %_Arguments(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(this, i+n, %_Arguments(i), 0, 0);

[Michael Starzinger, 2014/04/11 13:12:08]

This will break for primitive values as "this" because there is not ToObject
conversion anywhere and primitive values seem to be ignored by
Runtime_SetProperty.

Also this passes "sloppy" as the language mode, which causes this [[Put]] not to
throw if the element cannot be put according to [[CanPut]].

Both of the above cases are already broken right now. So I am fine with leaving
this as it is, but can we leave a TODO that this is a temporary workaround? You
can assign this TODO to me if you want.

[danno, 2014/04/16 14:34:38]

Done.

   }
 
   var new_length = n + m;
   this.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 1155 matching lines @@
   ));
 
   SetUpLockedPrototype(InternalPackedArray, $Array(), $Array(
     "join", getFunction("join", ArrayJoin),
     "pop", getFunction("pop", ArrayPop),
     "push", getFunction("push", ArrayPush)
   ));
 }
 
 SetUpArray();