[compiler-rt] [libFuzzer] always install signal handler with SA_ONSTACK (PR #147422)

[Mariusz Borsa via llvm-commits]

wrotki wrote:

On Vitaly's merge line above there's a 'revert' button. Or not, if you don't have merge permissions - in which case I can do it for you. If you can revert, add a short 'why' comment to it.

https://github.com/llvm/llvm-project/pull/147422