OK, this is the big one. We still keep using `#include` guards only
where we absolutely need to, but with each header now being valid in
isolation, this can now actually help *minimize* the length of each
translation unit's `#include` list. Turns out that after removing all
the duplicates, we only *actually* need to guard 29 headers across all
5 games.
Part of P0285, funded by [Anonymous] and iruleatgames.
Thanks to the required word alignment of the `switch` jump table in
TH05's dialog_op(), we do in fact have to slice dialog code into
exactly two* translation units. Three might have been better because we
would have only needed to compile this shared code once, but TH05 also
has one exclusive function in the area covered by this new shared
translation unit anyway. At least we can meaningfully share the actual
source files between games here.
* With an additional one at the end for now, because I absolutely had
to RE that EMS code in late 2021, but we'll catch up with that one in
the end.
Part of P0258, funded by [Anonymous] and Blue Bolt.
The `_animate()` convention doesn't *really* fit for a function that
also handles input, but I'd rather continue using the same convention
for every blocking multi-frame function.
Part of P0186, funded by [Anonymous] and Blue Bolt.
That's where TH04 crashes in Stage 5 without an EMS driver, but the
code is fine?! (Well, apart from its silly behavior in the Extra
Stage.)
Part of P0169, funded by Blue Bolt.
TH01-style unblitting from the back page of VRAM, in my TH04/TH05?!
It does make sense to suspend double buffering during dialog though,
and you probably don't want to call any custom stage rendering
functions just to effectively unblit a 128×128 pixel area.
Part of P0169, funded by Blue Bolt.