[llvm] [llvm] Support multiple save/restore points in mir (PR #119357)

[Elizaveta Noskova via llvm-commits]

enoskova-sc wrote:

@michaelmaitland, tank you for quick review and sorry for delay, I have a lot of another important tasks. I'm still working on this patch and will publish changes, as soon as possible.

https://github.com/llvm/llvm-project/pull/119357