runtime: improve coverage of TestCgoSigfwd
Currently, TestCgoSigfwd will pass incorrectly if the SIGSEGV that
originates in Go mistakenly goes to the C SIGSEGV handler. Fix this by
adding a signal-atomic variable that tracks what the expected behavior
is.
Change-Id: Id2a9fa3b209299dccf90bb60720b89ad96838a9c
Reviewed-on: https://go-review.googlesource.com/c/go/+/443072
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>