Turns out the inlining behavior of `const` variables at global scope
that we've been relying on lately is actually exclusive to C++ mode…
once again!
Part of P0133, funded by [Anonymous].
Nice to see that Borland C++ optimizes bit-tests to cover just the high
or low byte of a word if possible, and that these don't have to be
two-byte structures after all.
Completes P0114, funded by Lmocinemod.
The pascal calling convention for TH03's input mode functions actually
sort of matters, since we have this nice function pointer type that
expects pascal.
nmlgc