message: make ~vPreprocessor virtual
diff: @@ -47,7 +47,7 @@ class vPreprocessor : public verilogPreprocBaseVisitor {
  std::vector<std::string> &stack_incfile,
  unsigned int mode=VERILOG2001,
  size_t include_depth_limit=100);
  - ~vPreprocessor();
  + virtual ~vPreprocessor();
  virtual antlrcpp::Any visitResetall(verilogPreprocParser::ResetallContext * ctx);
  virtual antlrcpp::Any visitCelldefine(verilogPreprocParser::CelldefineContext * ctx);
  