misc/cgo/testsanitizers: terminate commands with SIGQUIT if hung

misc/cgo/testsanitizers: terminate commands with SIGQUIT if hung

If the test hangs due to a deadlock in a subprocess, we want a
goroutine dump of that process to figure out the nature of the
deadlock. SIGQUIT causes the Go runtime to produce exactly
such a dump (unless the runtime itself is badly deadlocked).

For #52998.

Change-Id: Id9b3ba89d8f705e14f6cd789353fc2b7f4774ad3
Reviewed-on: https://go-review.googlesource.com/c/go/+/407954
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Bryan Mills <bcmills@google.com>
Auto-Submit: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>