[PATCH] signal: Deprecate additional legacy signal handling functions

[Florian Weimer]

* Florian Weimer:

> This needs a few test adjustments: In some cases, sigignore was
> used for convenience (replaced with xsignal with SIG_IGN).  Tests
> for the deprecated functions need to disable
> -Wdeprecated-declarations.

I think we should deprecate the sigmask macro as well, so I'm going to
post a revised patch.

Thanks,
Florian