Enhance OpenMP parser tests from r197553 / r197598

Move some of the verifier directives away from the end of the pragma line.

This ensures that the diagnostics relate to the trailing token being tested and
not the verifier comments which are themselves part of the token stream.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@197616 91177308-0d34-0410-b5e6-96231b3b80d8