[llvm] Use TargetABI to assign default-target features in getDefaultSubtargetFeatures (PR #100833)

[Eric Christopher via llvm-commits]

echristo wrote:

So we cache a bunch of module stuff in the TargetMachine itself. Is there a reason why we wouldn't want to do the same with the abi string? i.e. I'm not sure we need to propagate the entire module down. Also do you have some code that uses this offhand that we can take a look at? I'd like to see the API use if that makes sense?

Thanks!

https://github.com/llvm/llvm-project/pull/100833