[llvm] [ARM] Stop gluing ALU nodes to branches / selects (PR #116970)

[Simon Tatham via llvm-commits]

https://github.com/statham-arm commented:

This is a big patch, but it's my absolute favourite kind: reduces the total amount of code _and_ makes things better! Overall the diff stats are negative in `llvm/lib` _and_ in `llvm/test`.

I didn't read absolutely all of the code diffs through, but I did spot-check a few things and came across a couple more tiny regressions, which I've highlighted just in case you happen to know what caused them. But I agree with you that this seems overall a good thing, and knock-on effects on scheduling can be dealt with later. (Also, this patch is big enough by itself and doesn't need extra things folded into it!)

https://github.com/llvm/llvm-project/pull/116970