[profiling] Tighten test cases which refer to "profn" vars. NFC.

The frontend can't see "__profn" profile name variables after IRGen
because llvm throws these away now. Tighten up some test cases which
checked for the non-existence of those variables.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@295528 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed