Bus network topology support?

[Hydreigon223]

Some arcade games (not using ethernet based logic) would send frames/packets to all nodes simultaneously as opposed to sending frames/packets to certain nodes in a sequential order ring. Even if most games that linked through a bus had their networking hardware/logic supported, it'd only be possible to link two Mame instances. The question comes down to how can we direct a network frame/packet to all Mame instances simultaneously?

The problems previously mentioned in #9090 were the reason why I opened this issue.