Add methods to extras' InternalPackedArray

src/js/array.js

Index: src/js/array.js
diff --git a/src/js/array.js b/src/js/array.js
index 462e5281374689929ff2fadb8e241ff6a38ba114..ade512a0e639e66d5746efe131b9e5114fb24206 100644
--- a/src/js/array.js
+++ b/src/js/array.js
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-(function(global, utils) {
+(function(global, utils, extrasUtils) {
 
 "use strict";
 
@@ -1624,6 +1624,17 @@ utils.SetUpLockedPrototype(InternalPackedArray, GlobalArray(), [
   "shift", getFunction("shift", ArrayShift)
 ]);
 
+// V8 extras get a separate copy of InternalPackedArray. We give them the basic
+// manipulation methods.
+utils.SetUpLockedPrototype(extrasUtils.InternalPackedArray, GlobalArray(), [
+  "push", getFunction("push", ArrayPush),
+  "pop", getFunction("pop", ArrayPop),
+  "shift", getFunction("shift", ArrayShift),
+  "unshift", getFunction("unshift", ArrayUnshift),
+  "splice", getFunction("splice", ArraySplice),
+  "slice", getFunction("slice", ArraySlice)
+]);
+
 // -------------------------------------------------------------------
 // Exports