[llvm] [X86] Add FeatureINVLPGB and CPUID handling for INVLPGB/TLBSYNC instructions (PR #121570)

[Phoebe Wang via llvm-commits]

phoebewang wrote:

> > I think compiler doesn't need aware of a feature if it never generates the instructions.
> 
> OK - are we consistent with this approach though?

I think so, [here](https://github.com/llvm/llvm-project/pull/113524) is a recent example.

https://github.com/llvm/llvm-project/pull/121570