Convert VAR16VISIBLE, VAR16EXPORT, and VAR32VISIBLE to VARFSEG.

Convert all users of the alternative variable exports to VARFSEG.
There isn't a significant distinction between the existing types of
exports, so it's simpler to just use one type going forward.

The new VARFSEG declaration is only emitting when in 32bit mode, so
update and move some variables as needed.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
25 files changed