There is no reason to limit sigaltstack syscall to just a few
architectures and pretend it is not implemented for others.
If some architecture is not ready for this, that architecture
should be fixed instead.
This fixes LP#1516408.
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>