[llvm] [LoopInterchange] Add metadata to control loop-interchange (PR #127474)

[Ryotaro Kasuga via llvm-commits]

https://github.com/kasuga-fj commented:

Hi @Meinersbur  .Thank you for all the help and insights on the other day. I fixed the implementation and updated the description of the PR, could you please check again? Thanks!

https://github.com/llvm/llvm-project/pull/127474