[llvm] [CodeGen] Introduce MI flag for Live Range split instructions (PR #117543)

[Christudasan Devadasan via llvm-commits]

cdevadas wrote:

### Merge activity

* **Jan 9, 12:40 PM UTC**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.com/github/pr/llvm/llvm-project/117543).


https://github.com/llvm/llvm-project/pull/117543