One fewer magic number. And one more deliberate dependency on a
PC-98-specific hardware constant, to further drive home just how
unportable these games are, even once decompilation will be complete.
Part of P0105, funded by Yanga.
tiles_invalidate_around() must have had the hardest function signature
to figure out in all of PC-98 Touhou… because it seems impossible to
handle all three ways of passing parameters. No way around separately
declaring it in every translation unit then, with the parameter list
expected by that segment's code generation.
Part of P0089, funded by [Anonymous] and Blue Bolt.
nmlgc