(set_conflicts): Resolve all conflicts, not just

the first one.  This change is from Paul Hilfinger, and it fixes
regression reported by Werner Lemberg in
<http://mail.gnu.org/archive/html/bug-bison/2003-04/msg00026.html>.

(resolve_sr_conflict): Don't invoke state_errs_set
unless one or more tokens have been explicitly made errors.
Otherwise, the above change causes Bison to abort.