[llvm] [MemProf] Support cold-only and min hint when optimizing existing hot/cold new (PR #218803)

[Snehasish Kumar via llvm-commits]

https://github.com/snehasish approved this pull request.

thanks, lgtm.

The decription is a bit stale now since it explicitly enumerates the two cases.

https://github.com/llvm/llvm-project/pull/218803