message: Respect sess.overflow_checks()
diff: @@ -874,6 +874,10 @@ pub fn trans_checked_int_binop<'a, 'tcx: 'a>(
  out_ty: Ty<'tcx>,
  signed: bool,
  ) -> CValue<'tcx> {
  + if !fx.tcx.sess.overflow_checks() {
  + return trans_int_binop(fx, bin_op, in_lhs, in_rhs, out_ty, signed);
  + }
  +
  if bin_op != BinOp::Shl && bin_op != BinOp::Shr {
  assert_eq!(
  in_lhs.layout().ty,
  