fix the second part of rdar://8366474 - clang fails to parse ObjC selectors...

fix the second part of rdar://8366474 - clang fails to parse ObjC selectors with '::', when :: isn't the first part of the selector.




git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@128344 91177308-0d34-0410-b5e6-96231b3b80d8