swift234

[ClangImporter] If a protocol and a class have the same name, add "Protocol".

.../if/ the protocol and the class are from the same top-level Clang module.
If not, the protocol is /not/ renamed, and users will have to disambiguate
with module qualification.

This kills our hardcoded "RenamedProtocols" list; it turns out this pattern
is more common than we thought /and/ leads to cross-referencing issues.

<rdar://problem/16206627>

Swift SVN r18809