[clang] [clang] Improve diagnostic on [[nodiscard]] attribute (PR #112521)

[Yihe Li via cfe-commits]

Mick235711 wrote:

> Side note: please try to avoid force-pushing in the future as that makes it really annoying to try and figure out what has changed since the last review. We always squash on merge anyway, so a clean commit history on a pr is irrelevant.
Oh, sorry about that, I don't usually force push, but I assumed that LLVM PRs should be one-commit only when I see a similarly-worded line in the contributing guidelines. My bad.

https://github.com/llvm/llvm-project/pull/112521