[clang] [Driver][X86] Add -m[no-]apxf to m_x86_Features_Group (PR #140874)

[Nico Weber via cfe-commits]

nico wrote:

Looks like this breaks tests on macOS: http://45.33.8.238/macm1/107398/step_6.txt

Please take a look and revert for now if it takes a while to fix.

https://github.com/llvm/llvm-project/pull/140874