[llvm] [Support] Don't re-raise signals sent from kernel (PR #145759)

[Peter Collingbourne via llvm-commits]

pcc wrote:

Not all crash signals sent by the kernel are synchronous (will automatically reraise). MTE asynchronous tag check faults are an example of a signal that will not reraise. Chromium would previously attempt to reraise these signals by returning from the signal handler as this PR proposes to do, which led to asynchronous tag check faults being ignored.

I fixed this bug in Chromium by using a different API to reraise the signal that preserves siginfo: https://chromium-review.googlesource.com/c/crashpad/crashpad/+/3300991

We should probably use this API at least on Linux.

https://github.com/llvm/llvm-project/pull/145759