[Reduction] #576-667: emu086.asm
[Reduction] #668-669: pow10
Move the stack segment into its own slice

Saves 141 lines, and we'll need to ASSUME it in the upcoming floating-point
slices.
[Reduction] #670-672: e087_Trap

I guess this marks the final demystification of how segment declarations work
and how they are compiled. However, it only really makes sense for anything
outside the TEXT segment, like these floating-point functions. As long as the
slices aren't immediately next to each other, it would still be annoying to
have segment declarations inside of them, since we'd have to copy-paste these
declarations around every INCLUDE directive...