/* We create a forwarder bb (5) for all edges leaving this region
(3->5, 4->5). All other edges leading to the same bb, are moved
to a new bb (6). If these edges where part of another region (2->5)
/* We create a forwarder bb (5) for all edges leaving this region
(3->5, 4->5). All other edges leading to the same bb, are moved
to a new bb (6). If these edges where part of another region (2->5)