[libc-commits] [libc] [libc] Enable `-Wunused` and clean up found instances (PR #96949)

[Arvind Sudarsanam via libc-commits]

asudarsa wrote:

> Well, I might not be checking the right way, I did not see any warnings show up (apart from `-undefined`) when doing `ninja -C build`.
> 
> How would you do it @SchrodingerZhu ?

One possible way might be to reintroduce the unused variables mentioned in the comment here (https://github.com/llvm/llvm-project/pull/96591#discussion_r1653050200) and rebuild to see if warnings are emitted with your change.

https://github.com/llvm/llvm-project/pull/96949