[llvm] [MLGO] Model selection for models lowered through EmitC (PR #212650)

[ioana ghiban via llvm-commits]

https://github.com/ioghiban requested changes to this pull request.

Thank you for putting this together so promptly. I added some high level comments, mainly on naming and Coding Standards. Will dive deeper once the patch is marked ready.

https://github.com/llvm/llvm-project/pull/212650