Support C11 _Atomic type qualifier. This is more-or-less just syntactic sugar for the _Atomic type specifier.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@178210 91177308-0d34-0410-b5e6-96231b3b80d8
Remove outdated FIXME.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@178211 91177308-0d34-0410-b5e6-96231b3b80d8