[clang] [compiler-rt] [llvm] [X86] Sync multiversion cpu subtypes and vendors with libgcc and refactor internal cpu type tables (PR #171172)

[Phoebe Wang via llvm-commits]

phoebewang wrote:

I'm always nervous seeing large changes without testing. Since the target is to match with libgcc, is it possible to verify it with GCC tests. I know llvm-test-suite contains some GCC tests. So it would be good to add them there. And a local verification is still better than none, if adding GCC tests is impossible.

https://github.com/llvm/llvm-project/pull/171172