clone_methods_before_find

clone the methods object before we search it, because the methods alter the structure by adding super class's methods to it. This ends up corrupting our in-memory copy of the metabase, so that a class like UIPanGestureRecognizer gets the super interface (UIGestureRecognizer)'s methods added to it's entry, and we end up thinking a method like initWithTarget lives on the subclass and not the parent.