Add game event for train crash

src/openttd.cpp

@@ -1813,5 +1813,6 @@ char *DumpGameEventFlags(GameEventFlags events, char *b, const char *last)
 	dump('n', GEF_RELOAD_NEWGRF);
 	dump('t', GEF_TBTR_REPLACEMENT);
 	dump('D', GEF_DISASTER_VEH);
+	dump('c', GEF_TRAIN_CRASH);
 	return b;
 }

src/openttd.h

@@ -93,6 +93,7 @@ enum GameEventFlags : uint32 {
 	GEF_RELOAD_NEWGRF        = 1 << 2, ///< (n) ReloadNewGRFData() has been called
 	GEF_TBTR_REPLACEMENT     = 1 << 3, ///< (t) CMD_TEMPLATE_REPLACE_VEHICLE has been called
 	GEF_DISASTER_VEH         = 1 << 4, ///< (D) A disaster vehicle exists or has been created
+	GEF_TRAIN_CRASH          = 1 << 5, ///< (c) A train crash has occurred
 };
 DECLARE_ENUM_AS_BIT_SET(GameEventFlags)
 

src/train_cmd.cpp

@@ -3540,6 +3540,8 @@ uint Train::Crash(bool flooded)
 		HideFillingPercent(&this->fill_percent_te_id);
 	}
 
+	RegisterGameEvents(GEF_TRAIN_CRASH);
+
 	pass += this->GroundVehicleBase::Crash(flooded);
 
 	this->crash_anim_pos = flooded ? 4000 : 1; // max 4440, disappear pretty fast when flooded