[COMMITTED PATCH] Add SIGWINCH to generic <bits/signum.h>.

[Roland McGrath]

> On 07/23/2015 07:46 PM, Roland McGrath wrote:
> > The only configuration affected by this is NaCl.  I've declared it a "bug
> > fix" because all real-world POSIX systems have SIGWINCH, so the "generic"
> > GNU API should include it.
> 
> If it's a publicly visible bug it should have a bug filed for it.

Well, it was only visible in the arm-nacl configuration, and there has not
been a release that had that configuration.  So so such bugs were actually
user-visible for certain definitions of user.