Remove unnecessary use of "virtual"

These functions are neither provided by any base classes nor is anyone
inheriting from these classes.

Author: tautschnig

jbmc/src/janalyzer/janalyzer_parse_options.h

@@ -162,11 +162,11 @@ class janalyzer_parse_optionst : public parse_options_baset, public messaget
   ui_message_handlert ui_message_handler;
   goto_modelt goto_model;
 
-  virtual void register_languages();
+  void register_languages();
 
-  virtual void get_command_line_options(optionst &options);
+  void get_command_line_options(optionst &options);
 
-  virtual bool process_goto_program(const optionst &options);
+  bool process_goto_program(const optionst &options);
   bool set_properties();
 
   virtual int perform_analysis(const optionst &options);

jbmc/src/jdiff/jdiff_parse_options.h

@@ -59,15 +59,14 @@ class jdiff_parse_optionst : public parse_options_baset, public jdiff_languagest
   ui_message_handlert ui_message_handler;
   jdiff_languagest languages2;
 
-  virtual void get_command_line_options(optionst &options);
+  void get_command_line_options(optionst &options);
 
   virtual int get_goto_program(
     const optionst &options,
     jdiff_languagest &languages,
     goto_modelt &goto_model);
 
-  virtual bool
-  process_goto_program(const optionst &options, goto_modelt &goto_model);
+  bool process_goto_program(const optionst &options, goto_modelt &goto_model);
 
   void preprocessing();
 };

src/goto-diff/goto_diff_parse_options.h

@@ -59,16 +59,14 @@ class goto_diff_parse_optionst:
   ui_message_handlert ui_message_handler;
   goto_diff_languagest languages2;
 
-  virtual void get_command_line_options(optionst &options);
+  void get_command_line_options(optionst &options);
 
   virtual int get_goto_program(
     const optionst &options,
     goto_diff_languagest &languages,
     goto_modelt &goto_model);
 
-  virtual bool process_goto_program(
-    const optionst &options,
-    goto_modelt &goto_model);
+  bool process_goto_program(const optionst &options, goto_modelt &goto_model);
 
   void preprocessing();
 };

src/goto-instrument/goto_instrument_parse_options.h

@@ -128,7 +128,7 @@ class goto_instrument_parse_optionst:
 
 protected:
   ui_message_handlert ui_message_handler;
-  virtual void register_languages();
+  void register_languages();
 
   void get_goto_program();
   void instrument_goto_program();