message: Add missing override on overridden virtual method (NFC)
diff: @@ -3252,7 +3252,8 @@ public:
  }
  /// Parse an optional arrow followed by a type list.
  - ParseResult parseOptionalArrowTypeList(SmallVectorImpl<Type> &result) {
  + ParseResult
  + parseOptionalArrowTypeList(SmallVectorImpl<Type> &result) override {
  if (!parser.consumeIf(Token::arrow))
  return success();
  return parser.parseFunctionResultTypes(result);
  