[llvm] [Draft] Support save/restore point splitting in shrink-wrap (PR #119359)

[Alex Bradbury via llvm-commits]

asb wrote:

@enoskova-sc I've started looking at applying this to the latest HEAD in order to do some testing. If you've already done such a rebase / merge then that would be helpful!

https://github.com/llvm/llvm-project/pull/119359