[PGO] Add PGO support at -O0 in the experimental new pass manager

Add PGO support at -O0 in the experimental new pass manager to sync the
behavior of the legacy pass manager.

Also change the test of gcc-flag-compatibility.c for more complete test:
(1) change the match string to "profc" and "profd" to ensure the
    instrumentation is happening.
(2) add IR format proftext so that PGO use compilation is tested.

Differential Revision: https://reviews.llvm.org/D64029

llvm-svn: 367628