Potentially save on space for an actor in the future (#3553)
Potentially save on space for an actor in the future (#3553)

While doing a separate review together, Sylvan noticed that while not
currently wasteful, that the layout of pony_actor_t could end up in
resulting in excess alignment packing in the future.
sgebbie/ponyc,ponylang/ponyc,ponylang/ponyc,sgebbie/ponyc,dipinhora/ponyc,jemc/ponyc,jemc/ponyc,jemc/ponyc,sgebbie/ponyc,dipinhora/ponyc,sgebbie/ponyc,ponylang/ponyc,dipinhora/ponyc,sgebbie/ponyc