docs: private LabeledStatement matchJumpLabelName()
          throws IOException
      {
          LabeledStatement label = null;
  
          if (peekTokenOrEOL() == Token.NAME) {
              consumeToken();
              if (labelSet != null) {
                  label = labelSet.get(ts.getString());
              }
              if (label == null) {
                  reportError("msg.undef.label");
              }
          }
  
          return label;
      }