ULTIMA8: Slow down to walk or step if animation ends off land.

This fixes most cases of running down stairs causing a jump. The original game tries harder to not end off land, but controls worse due to that.

engines/ultima/ultima8/world/actors/u8_avatar_mover_process.cpp

@@ -691,6 +691,13 @@ void U8AvatarMoverProcess::step(Animation::Sequence action, Direction direction,
 		action = Animation::stand;
 	}
 
+	if (action == Animation::walk && res == Animation::END_OFF_LAND) {
+		action = Animation::step;
+	}
+
+	if (action == Animation::run && res == Animation::END_OFF_LAND) {
+		action = Animation::walk;
+	}
 
 	bool moving = (action == Animation::run || action == Animation::walk);