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

[Roland McGrath]

> Should NaCl get mention in the README?

I was going to add it to the list when I added the NEWS item.  But then I
noticed that the list of tuples is titled ".. for using Linux kernels" and
README and failed to notice the whole separate paragraph about Hurd.  As is
the case for Hurd, people interested in the NaCl configuration will be
starting from NaCl information and get their pointers to building glibc
that way.  I don't think anybody getting glibc and not knowing about NaCl
support already will be looking at README to find it.