Store crash/desync logs in crash/desync savegame

Add console command to dump loaded debug log

src/debug.h

@@ -14,6 +14,7 @@
 
 #include "cpu.h"
 #include <chrono>
+#include <string>
 
 /* Debugging messages policy:
  * These should be the severities used for direct DEBUG() calls
@@ -58,6 +59,9 @@ extern int _debug_sound_level;
 extern int _debug_random_level;
 #endif
 
+extern const char *_savegame_DBGL_data;
+extern std::string _loadgame_DBGL_data;
+
 void CDECL debug(const char *dbg, const char *format, ...) WARN_FORMAT(2, 3);
 
 char *DumpDebugFacilityNames(char *buf, char *last);