Re-land r25392 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 de41d689b5db37c29c62f8b628b0692129d497e9..62f04b831aeb91b86630e487cdaa4ae64d25b621 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -1827,6 +1827,12 @@ 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) {