message: Fix typo in comment (UTC -> UTS)
diff: @@ -2225,7 +2225,7 @@ mod tests {
  fn class_special_escaped_set_chars() {
  // These tests ensure that some special characters require escaping
  // for use in character classes. The intention is to use these
  - // characters to implement sets as described in UTC#18 RL1.3. Once
  + // characters to implement sets as described in UTS#18 RL1.3. Once
  // that's done, these tests should be removed and replaced with others.
  assert_eq!(p(r"[\[]"), Expr::Class(class(&[('[', '[')])));
  assert_eq!(p(r"[&]"), Expr::Class(class(&[('&', '&')])));
  @@ -2801,7 +2801,7 @@ mod tests {
  fn error_class_unsupported_char() {
  // These tests ensure that some unescaped special characters are
  // rejected in character classes. The intention is to use these
  - // characters to implement sets as described in UTC#18 RL1.3. Once
  + // characters to implement sets as described in UTS#18 RL1.3. Once
  // that's done, these tests should be removed and replaced with others.
  test_err!("[[]", 1, ErrorKind::UnsupportedClassChar('['));
  test_err!("[&&]", 2, ErrorKind::UnsupportedClassChar('&'));
  