Both player/player.hpp and resident.hpp (in case of TH03's PLAYER_COUNT)
and th04/shared.hpp (in case of TH04/TH05's MAIN_STAGE_COUNT) have way
too much additional stuff that we don't want to include everywhere we
need these constants. So let's try this "no types allowed" approach
instead… maybe that'll work out for once.
Part of P0076, funded by [Anonymous] and -Tom-.