[Profile] Enable binary profile correlation for Mach-O binaries (#179937)

The existing ELF/COFF correlation code mostly "just works" on Mach-O
files, with one gotcha: on disk, the pointers in `__llvm_covdata` are
stored in an encoded format due to dyld fixup chains. (In memory, they
would normally be fixed up at load time in a running binary, but the
correlator only looks at the on-disk values.)

LLVM's Mach-O reader knows how to decode the format, so this patch walks
the fixup table to create a set of mappings that the correlator can use
to resolve the values.

rdar://168259786

GitOrigin-RevId: cd47ae9f8ff9afa46209806e94bfadb0056049c5