[llvm] [RISCV] Combine (mul (zext, zext)) -> (zext (mul (zext, zext))) (PR #86465)

[Luke Lau via llvm-commits]

lukel97 wrote:

> Luke, are you going to do a follow up here to add basic logical ops? OR/XOR/AND would all seem legal here, and while not known to be particularly interesting, we should probably handle for completeness sake. If not, let me know and I'll post something.

Yup, I had chucked them into alive2 already and they seem to be fine. I believe we can also do {u,s}{div,rem} too. Will post patches for them shortly.

https://github.com/llvm/llvm-project/pull/86465