message: fix test-cargo-miri
diff: @@ -55,7 +55,7 @@ fn do_panic() { // In large, friendly letters :)
  // FIXME: see above
  #[test]
  -#[allow(const_err)]
  +#[allow(unconditional_panic)]
  #[cfg_attr(not(windows), should_panic(expected="the len is 0 but the index is 42"))]
  fn fail_index_check() {
  #[cfg(not(windows))]
  