[llvm] [MIR] Add missing noteNewVirtualRegister callbacks (PR #111634)

[Akshat Oke via llvm-commits]

optimisan wrote:

### Merge activity

* **Oct 14, 4:57 AM EDT**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/111634).


https://github.com/llvm/llvm-project/pull/111634