message: Don't panic on reported const eval errors
diff: @@ -85,7 +85,10 @@ pub fn force_eval_const<'tcx>(
  match const_.val {
  ConstKind::Unevaluated(def_id, ref substs) => {
  let substs = fx.monomorphize(substs);
  - fx.tcx.const_eval_resolve(ParamEnv::reveal_all(), def_id, substs, None).unwrap()
  + fx.tcx.const_eval_resolve(ParamEnv::reveal_all(), def_id, substs, None).unwrap_or_else(|_| {
  + fx.tcx.sess.abort_if_errors();
  + unreachable!();
  + })
  }
  _ => fx.monomorphize(&const_),
  }
  