Move Add to the elements accessor for everything but dictionary-arguments

src/elements.h

Index: src/elements.h
diff --git a/src/elements.h b/src/elements.h
index 0051c2e9f41b94686849ec64d78d667b01c3e580..b98e84ecea38ef1511ccd70896339b9c34221557 100644
--- a/src/elements.h
+++ b/src/elements.h
@@ -144,6 +144,9 @@ class ElementsAccessor {
                            Handle<FixedArrayBase> backing_store, uint32_t index,
                            Handle<Object> value,
                            PropertyAttributes attributes) = 0;
+  virtual void Add(Handle<JSObject> object, uint32_t index,
+                   Handle<Object> value, PropertyAttributes attributes,
+                   uint32_t new_capacity) = 0;
 
  protected:
   friend class SloppyArgumentsElementsAccessor;