Increase verbosity of some assertion failure messages

src/timetable_cmd.cpp

@@ -803,7 +803,7 @@ void UpdateVehicleTimetable(Vehicle *v, bool travelling)
 			return;
 		}
 	} else {
-		assert(real_timetable_order == real_current_order);
+		assert_msg(real_timetable_order == real_current_order, "%u, %u", v->cur_real_order_index, v->cur_timetable_order_index);
 	}
 
 	if (just_started) return;

src/train_cmd.cpp

@@ -200,7 +200,8 @@ void Train::ConsistChanged(ConsistChangeFlags allowed_changes)
 		const RailVehicleInfo *rvi_u = RailVehInfo(u->engine_type);
 
 		/* Check the this->first cache. */
-		assert(u->First() == this);
+		assert_msg(u->First() == this, "u: %s, this: %s",
+				scope_dumper().VehicleInfo(u), scope_dumper().VehicleInfo(this));
 
 		/* update the 'first engine' */
 		u->gcache.first_engine = this == u ? INVALID_ENGINE : first_engine;