[llvm] [SelectionDAG] Fold (avg x, 0) -> x >> 1 (PR #85581)

[David Green via llvm-commits]

https://github.com/davemgreen commented:

I think for vectors this might already be handled, and I don't know if there are any architectures that use these nodes for scalars.

https://github.com/llvm/llvm-project/pull/85581