bug#19468: 25.0.50; UI inconveniences with M-.

[Eli Zaretskii]

> Cc: 19468@debbugs.gnu.org
> From: Dmitry Gutov <dgutov@yandex.ru>
> Date: Sat, 2 May 2015 20:35:56 +0300
> 
> On 05/02/2015 04:41 PM, Eli Zaretskii wrote:
> > There's some tricky logic in ID Utils wrt when to report relative file
> > names and when not, and I guess CEDET doesn't expect absolute file
> > names, especially not on Windows.  With the patch below, it works for
> > me both ways.
> 
> It doesn't break anything here, please go ahead.

Done, with a couple more such blunders.  My favorite is this (from
cedet/semantic/bovine/gcc.el):

                (when (file-accessible-directory-p path)
                  (when (if (memq system-type '(windows-nt))
                            (/= ?/ (nth 1 chars))  <<<<<<<<<<<<<<<<
                          (= ?/ (nth 1 chars)))    <<<<<<<<<<<<<<<<
                    (add-to-list 'inc-path
                                 (expand-file-name (substring line 1))

which evidently wants to make sure the file name is in absolute form.