Objective-C [Sema]. Fixes a bug in comparing qualified
Objective-C pointer types. In this case, checker incorrectly
claims incompatible pointer types if redundant protocol conformance 
is specified. rdar://18491222


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@219630 91177308-0d34-0410-b5e6-96231b3b80d8