bug#23003: 25.1.50; --with-x-toolkit options cause the build to fail.

[Keith David Bershatsky]

It appears that an apology may be needed with respect to launching bug report 
for 23003 in that the problem appears to be caused by first building Emacs 
using the `--with-ns` option, followed by building Emacs again using 
`--with-x`.  I have never used `make clean`, but that appears to resolve the 
issues with gtk3, athena and motif.

Your patch applies to the master branch, instead of the emacs-25 branch.  But, 
the patch may not be necessary . . . .

Even when switching between athena and motif, it is apparently necessary to run 
`make clean` before running a new configure and make.

If it is not inconvenient, perhaps leave this ticket open for a reasonable 
period of time.  I will be building using all of the options over the next few 
weeks and will make a note on my calendar to report back.

I would also like to apologize for my unfamiliarity with a patch containing 
things like:

  From 09154cfbe27159d5a9f0acd3e3ae89c6969f694d Mon Sep 17 00:00:00 2001
  From: Paul Eggert <eggert@cs.ucla.edu>
  Date: Thu, 17 Mar 2016 23:45:02 -0700
  Subject: [PATCH] Port to GTK with strict C99 compiler

I had never seen such a thing before and erroneously assumed it would cause 
problems when applying the patch.

So, in a nutshell, no changes for now please. . .  Thank you for all your hard 
work, and my apologies for potentially wasting your time.

Thanks,

Keith