[llvm] [GlobalISel] Add `combine_or_of_and` from SelectionDAG (PR #198754)

[David Green via llvm-commits]

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

> hey @davemgreen, unfortunately GISEL does not support this now with the MIR patterns, it could be one of the next things I could work on. do you think this PR should wait until then, or is it good to go? thanks for the feedback!

The sooner the better, to prevent us adding a lot of patterns that just need rewriting. Can you add a FIXME in the meantime?

Otherwise LGTM

https://github.com/llvm/llvm-project/pull/198754