swift234

When attempting to obtain the context type of a type extension, we were never taking into account the fact that the extended type could be potentially be unbound.
(This could occur, for instance, via a forward reference to a member defined in an extension to a generic type.)  This problem has been popping up a lot lately, and
was making some of the recent runtime work difficult.  (rdar://problem/16481483)

Swift SVN r15805