Fix 98ac75e: non deterministic handling of train crashes (#15338)

src/train_cmd.cpp

@@ -3233,8 +3233,10 @@ static uint CheckTrainCollision(Vehicle *v, Train *t)
 	/* Happens when there is a train under bridge next to bridge head */
 	if (abs(v->z_pos - t->z_pos) > 5) return 0;
 
-	/* crash both trains */
-	return TrainCrashed(t) + TrainCrashed(coll);
+	/* Crash both trains. Two statements required to guarantee execution
+	 * order because RandomRange() is involved. */
+	uint num_victims = TrainCrashed(t);
+	return num_victims + TrainCrashed(coll);
 }
 
 /**