bug#18463: play-sound crashes emacs if file does not exist

[Eli Zaretskii]

> Date: Fri, 12 Sep 2014 23:10:43 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 18463@debbugs.gnu.org
> 
> The latest pretest version of 24.4 signals an error saying
> 
>    This Emacs binary lacks sound support

This was due to a bug in the build process: the sound support
functions were not compiled into the Windows build.  Now fixed on the
emacs-24 branch (revision 117496).  So something good already resulted
from this bug report; thanks.

With that bug fixed, an existing sound file is played, while a
non-existing one causes this error message to be displayed:

  The open mciSendString command failed to open the specified sound file.
  Error: Cannot find the specified file.  Make sure the path and filename are 
correct.

This is on XPSP2; I will try on Windows 7 when I have time.