Created attachment 642776 [details] [diff] [review] v1 The default behaviour for objects without a typeOf hook is to return "object". In the most cases we actually want that and don't need to implement that hook and explicitly return JSTYPE_OBJECT. This is mostly done to prevent bailouts for MTypeOfIs on dense arrays in IonMonkey, which are probably common.
Created attachment 642778 [details] [diff] [review] v1 Forgot to refresh.
We could also land this on m-i.