[PGO] Relax test cases in PGO instrumentation

Fix buildbot failure for clang-x86_64-linux-selfhost-modules.
http://lab.llvm.org:8011/builders/clang-x86_64-linux-selfhost-modules/builds/8866
The failing test cases are newly added from r254021. It seems the IR has a
different order in this platform. In this patch, I temporarily relax the test
case to make the build green. I'll have a complete fix (more robust way to test)
soon.

llvm-svn: 254035