[llvm] [TableGen][NFCI] Simplify TypeSetByHwMode::intersect and make extensible (PR #81688)

[Krzysztof Parzyszek via llvm-commits]

https://github.com/kparzysz approved this pull request.

This makes sense.  Thanks!

Could you emphasize somewhere in a comment that this will only work for non-overlapping wildcards?

https://github.com/llvm/llvm-project/pull/81688