Use a stub in crankshaft for grow store arrays.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 61dfa44a3ff0abdef8dcaa232ef0f7c9eb53a043..d6c2fdc565bc70f896efb96a006052662fdb3a48 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -1849,6 +1849,12 @@ void JSObject::EnsureCanContainElements(Handle<JSObject> object,
 }
 
 
+bool JSObject::WouldConvertToSlowElements(Handle<Object> key) {
+  uint32_t index;
+  return key->ToArrayIndex(&index) && WouldConvertToSlowElements(index);
+}
+
+
 void JSObject::SetMapAndElements(Handle<JSObject> object,
                                  Handle<Map> new_map,
                                  Handle<FixedArrayBase> value) {