message: test discriminant_value intrinsic
diff: @@ -25,4 +25,9 @@ fn main() {
  assert_eq!(intrinsics::unlikely(true), true);
  unsafe { intrinsics::forget(Bomb); }
  +
  + let _v = intrinsics::discriminant_value(&Some(()));
  + let _v = intrinsics::discriminant_value(&0);
  + let _v = intrinsics::discriminant_value(&true);
  + let _v = intrinsics::discriminant_value(&vec![1,2,3]);
  }
  