[llvm] [Transforms][Utils] Add LoopSplitUtils for iteration-space loop splitting (PR #205995)

[Ashutosh Nema via llvm-commits]

nema-ashutosh wrote:

Thanks for the review comments. I'll address the inline comments and add/update tests where needed. I agree the PR grew larger than expected, and I'll try to keep future changes more incremental and easier to review.

https://github.com/llvm/llvm-project/pull/205995