checkasm: msac: Fix signal handler recovery in msac_decode_bool*
checkasm: msac: Fix signal handler recovery in msac_decode_bool*

The signal handler does a longjmp back to the location of declare_func
when there's a signal. If declare_func is located within the check_func
block, it will just end up in an endless loop, retrying running the
failing tests again.

On linux, after resuming from the signal handler, the second signal
wouldn't trigger the signal handler but forcibly exit the process,
while on darwin, it would get stuck in an endless loop.

msac_decode_bool seems to be the only checkasm test with declare_func
within the check_func block.

videolan/dav1d