[clang] [Clang] Warn against unused parameters in C++ coroutines with `-Wunused-parameters` (PR #70567)

[Chuanqi Xu via cfe-commits]

https://github.com/ChuanqiXu9 commented:

Thanks for the very quick response. But I think it might be worthy to spend more time to find a light weight solution than RecursiveASTVisitors.

https://github.com/llvm/llvm-project/pull/70567