message: Test `SharedFlag` copying
diff: @@ -481,13 +481,18 @@ mod tests {
  #[test]
  fn shared_flag_sanity_check() {
  let flag = SharedFlag::new();
  + let copied = flag;
  assert!(!flag.is_set());
  + assert!(!copied.is_set());
  assert!(!flag.is_set());
  + assert!(!copied.is_set());
  flag.set();
  assert!(flag.is_set());
  + assert!(copied.is_set());
  assert!(flag.is_set());
  + assert!(copied.is_set());
  }
  }
  