[llvm] [LV] Apply urem folds to preheader (PR #213928)

[Ramkumar Ramachandra via llvm-commits]

https://github.com/artagnon commented:

The challenge with mass test updates is always reverting unwanted hunks :( If you use Magit or some other git frontend, it should make it easier?

https://github.com/llvm/llvm-project/pull/213928