The warning flag was introduced in the last Clang release:
https://github.com/llvm/llvm-project/commit/f62d18ff140f67a8776a7a3c62a75645d8d540b5

No-Try: true
Change-Id: I8210ee947ad1a459b9edd143e4a1f7b238b4f13e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3217191
Auto-Submit: Victor Gomes <victorgomes@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77312}