swift234

[ClangImporter] Protocol instance methods are also class methods on roots.

-respondsToSelector: is declared on the NSObject protocol, which is adopted
by the NSObject root class. The NSObject metaclass also extends NSObject,
so it also needs a respondsToSelector:. This effectively becomes a
+respondsToSelector: method on NSObject-the-class.

Change importMirroredProtocolMembers to actually do this, just like
importObjCMembers was changed in r11614 for instance methods declared
directly within the class.

Finishes <rdar://problem/13371711>.

Swift SVN r11881