[clang] [Clang] Preserve coroutine parameter referenced state during allocation function lookup (PR #217518)

[Yanzuo Liu via cfe-commits]

zwuis wrote:

Please add a release note entry to `clang/docs/ReleaseNotes.md`.

What if parameters are actually used by the allocation function? Can you add tests?

If I remember correctly, there is similar mechanism when initializing the promise object. Can you handle this case as well?

https://github.com/llvm/llvm-project/pull/217518