add documentation to read_goto_binary and read_object_and_link

Author: Daniel Kroening

src/goto-programs/read_goto_binary.h

@@ -19,25 +19,33 @@ class goto_modelt;
 class message_handlert;
 class symbol_tablet;
 
+// Read given goto binary
+// Does not update config
 bool read_goto_binary(
   const std::string &filename,
   symbol_tablet &,
   goto_functionst &,
   message_handlert &);
 
+// Read given goto binary
+// Does not update config
 bool read_goto_binary(
   const std::string &filename,
   goto_modelt &dest,
   message_handlert &);
 
 bool is_goto_binary(const std::string &filename);
 
+// Read given goto binary and link to existing context
+// Also updates config
 bool read_object_and_link(
   const std::string &file_name,
   symbol_tablet &,
   goto_functionst &,
   message_handlert &);
 
+// Read given goto binary and link to existing context
+// Also updates config
 bool read_object_and_link(
   const std::string &file_name,
   goto_modelt &,