gnulib's errno module was imported

[Eli Zaretskii]

> From: Yao Qi <yao@codesourcery.com>
> CC: <gregory.0xf0@gmail.com>
> Date: Fri, 14 Nov 2014 13:44:49 +0800
> 
> I am inclined to back "dirfd" (and "errno") module out.  As a result,
> gdb will not be compatible with LSB 3.0, but it is just a minor issue to
> me.  What do you think?

Is it possible to back out dirfd, and then add to GDB whatever glue
(borrowed from gnulib) that's needed to support LSB 3.0?  IOW, can we
support LSB 3.0 in our own code, either inspired or stolen from
gnulib?

IME, gnulib many times includes a lot of overhead in its solutions for
problems, while the minimal change to fix the specific problem can be
much more lightweight and simple.  the question is can we go this way
in this case?

Thanks.