[X86] Disable FixupSetCC for CodeGenOpt::None

It is an optimization pass, and should not run at -O0. Especially since Fast RA
will not do the required register coalescing anyway, so it's a loss even from
the optimization standpoint.

This also works around (but doesn't quite fix) PR28489.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275099 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed