Before commit a7d33b1c "(bug #3639) BoxOnPlaneSide rewrite" there
was more code here, but since then the only thing left is the
Invert24To16 function, to which I couldn't find any references since
the beginning of ioquake3's git history.
Resolves: https://github.com/ioquake/ioq3/issues/774
Signed-off-by: Simon McVittie <smcv@debian.org>
9f0280bca1