DiagnoseUnknownTypename always emits a diagnostic and returns true

Make it return void and delete the dead code in the parser that handled
the case where it might return false.  This has been dead since 2010
when John deleted Action.h.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@211248 91177308-0d34-0410-b5e6-96231b3b80d8
[OPENMP] Improved diagnostic messages for vars with the predetermined data sharing attributes and reformatting


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@211262 91177308-0d34-0410-b5e6-96231b3b80d8
[c++1z] Implement N3994: a range-based for loop can declare a variable with super-terse notation

  for (x : range) { ... }

which is equivalent to

  for (auto &&x : range) { ... }


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@211267 91177308-0d34-0410-b5e6-96231b3b80d8