[Bug lto/79851] diagnostics: replace '%s' with %qs in all diagnostics

["rguenth at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79851

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2017-03-06
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
A complication is that we use two different diagnostic machineries, where I
believe only one handles %qs and the other simply uses fprintf
(diagnostic*.[ch]
vs. errors.[ch]).  Some files are build both for generator programs (which use
errors.[ch]) and for GCC.  For example errors.c simply has

/* Similar, but say we got an internal error.  */

void
internal_error (const char *format, ...)
{
  va_list ap;

  va_start (ap, format);
  fprintf (stderr, "%s: Internal error: ", progname);
  vfprintf (stderr, format, ap);
  va_end (ap);
  fputc ('\n', stderr);
  exit (FATAL_EXIT_CODE);
}

(so those are also not marked for translation).