Fix bug #15933 with crashes in file-notify-tests on MS-Windows.

Fix bug #15933 with crashes in file-notify-tests on MS-Windows.

 Support w32 file notifications in batch mode.
 src/w32proc.c (sys_select): Don't wait on interrupt_handle if it is
 invalid (which happens in batch mode).  If non-interactive, call
 handle_file_notifications to store file notification events in the
 input queue.
 src/w32notify.c (send_notifications): Handle FRAME_INITIAL frames as
 well.
 src/w32inevt.c (handle_file_notifications): Now external, not
 static.
 src/w32term.h (handle_file_notifications): Provide prototype.
 src/emacs.c (main) [HAVE_W32NOTIFY]: When non-interactive, call
 init_crit, since init_display, which does that otherwise, is not
 called.