[llvm] Fix layering violation from #220073 (PR #220150)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 approved this pull request.

LGTM. I guess any inconsistency around TPC/LegacyPM should be deleted soon.

Might also be good to port bazel too and do a local build just to ensure that this does fix the layering violation. A lot of the `Transforms*` libraries seem to disable header parsing probably due to latent issues.

https://github.com/llvm/llvm-project/pull/220150