This patch uses one bit in profile version to differentiate Clang
instrumentation and IR level instrumentation profiles.
PGOInstrumenation generates a COMDAT variable __llvm_profile_raw_version so
that the compiler runtime can set the right profile kind.
PGOInstrumenation now checks this bit to make sure it's an IR level
instrumentation profile.
Differential Revision: http://reviews.llvm.org/D15540
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260146 91177308-0d34-0410-b5e6-96231b3b80d8