Improvements and fixes for name lookup with using directives, from Piotr Rak!

Also, put Objective-C protocols into their own identifier
namespace. Otherwise, we find protocols when we don't want to in C++
(but not in C).


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@63877 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed