It's not necessary for assigning `__seg` pointers to `far` ones, which
might even remove the <dos.h> dependency in some translation units.
Part of P0134, funded by [Anonymous].
Might seem inconsistent, given that the function initializes pointers
that are declared in planar.h… but it's always called from other game
initialization functions that don't require pc98.h or planar.h.
Part of P0133, funded by [Anonymous].
The same function appears unused in TH02's MAINE.EXE. Separate commit because
this was painful enough and we can link the C version into FUUIN.EXE right
now.
nmlgc