[libc-commits] [libc] [libc][NFC] Fix GCC volatile warning (PR #78509)

[Nick Desaulniers via libc-commits]

nickdesaulniers wrote:

consider adding the diagnostic you're addressing to the commit message (here and in future patches) to help reviewers understand precisely what you're addressing.

https://github.com/llvm/llvm-project/pull/78509