> This statement is more or less a duplicate of line 336. Would this change be better if the common lines were extracted into a method?

I thought about that but couldn't think of what to call such a method.  A good name for it would be `original_unbound_method_handle_from_ancestor_for`...but that's already taken by this method.

Ideally, I would have liked to put the `superclass_proxy` conditional in this method but the problem is that we have to explicitly skip the original proxy and go straight to the superclass proxy because the original proxy will already have a method double at this point (the act of stubbing a method creates the method double and then we get here), so this was the best I could come up with.