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

[David Sherwood via llvm-commits]

david-arm wrote:

> Ah, the trick is always selecting the hunks in the diff to stage -- Magit is just a nicer frontend to `git add -p`, so you stage just the urem changes in each file, and drop the rest? When the FileCheck pattern is different, you'd have to manually edit and rewrite it to the earlier pattern though, and I know the pain myself :(

OK, I've never heard of Magit and I've never used `git add -p` so two new things for me today. :)

If there are hundreds of files that need manually rewriting I'd rather just have a pre-commit PR that regenerates all the CHECK lines instead. This will be of more benefit to everyone I think, since others will hit exactly the same issue at some point.

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