[llvm] [ctxprof] Override type of instrumentation if `-profile-context-root` is specified (PR #128940)

[Mircea Trofin via llvm-commits]

mtrofin wrote:

### Merge activity

* **Feb 26, 10:55 PM EST**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/128940).


https://github.com/llvm/llvm-project/pull/128940