message: overflow checks should panic in all build configurations
diff: @@ -130,14 +130,14 @@ mod test {
  use super::SpIndex;
  #[test]
  - #[cfg_attr(debug_assertions, should_panic)]
  + #[should_panic]
  fn overflow_u16() {
  let b: u16 = u16::from_usize(131072); // 2^17
  println!("{}", b);
  }
  #[test]
  - #[cfg_attr(debug_assertions, should_panic)]
  + #[should_panic]
  fn negative_i16() {
  let b: i16 = -1;
  let a = b.index();
  