Currently we have pgo options defined in PassManagerBuilder.cpp only for instrument pgo, but not for sample pgo. We also have pgo options defined in NewPMDriver.cpp in opt only for new pass manager and for all kinds of pgo. They have some inconsistency.
To make the options more consistent and make tests writing easier, the patch let old pass manager to share the same pgo options with new pass manager in opt, and removes the options in PassManagerBuilder.cpp.
can we move this enum to header so that we won't duplicate in NewPMDriver.cpp?