[llvm] Fold (a % b) lt/ge (b-1) where b is a power of 2 (PR #72504)

[Yingwei Zheng via llvm-commits]

dtcxzyw wrote:

> The first version of the pull handled this: https://godbolt.org/z/sTrsj1aW4 gcc uses and with `-121`, can I create another pull, that handles this?

Sure!

https://github.com/llvm/llvm-project/pull/72504