[llvm] [X86] Don't always separate conditions in `(br (and/or cond0, cond1))` into separate branches (PR #81689)

[Simon Pilgrim via llvm-commits]

https://github.com/RKSimon commented:

LGTM cheers (with a couple of comments that we should followup - happy if you raise issues or want to look at them in the future).

Any other comments?

https://github.com/llvm/llvm-project/pull/81689