swift234

[Import as Member] Print full context in fixit

Due to swift_name and swift_newtype, we are frequently importing onto
different contexts. This was confusing the fixit logic for unavailable
swift2 names, as we were trying to use Clang names when the Swift name
might be totally different (and even a nested type). This change has a
two-fold effect:

1) Globals who are imported onto swift_newtype-ed typedefs should be
   considered ImportAsMember.
2) When printing out the name of an ImportAsMember Swift 3 decl, we
   need to print out a fully qualified context, which also uses the
   Swift names, not the Clang names.