runtime: in TestSpuriousWakeupsNeverHangSemasleep, wait for the runtime to register handlers
According to https://man7.org/linux/man-pages/man7/signal.7.html, the
default behavior of SIGIO is to terminate the program. The Go runtime
changes that behavior with its own signal handler, so the program will
terminate if we send the signal before the runtime has finished
setting up.
Fixes #49727
Change-Id: I65db66f5176831c8d7454eebc0138d825c68e100
Reviewed-on: https://go-review.googlesource.com/c/go/+/366255
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com> Reviewed-by: Ian Lance Taylor <iant@golang.org>