[libre-riscv-dev] using a stage chain in a stage

[Jacob Lifshay]

I'm trying to build the div pipe, however, the ispec and ospec need to
be different than the currently existing code since that is FP
specific, there needs to be additional io signals that are not
included in all the FP*Data classes. Additionally, I don't want to
just overwrite the existing FPDiv pipe code since I'm not planning on
adding FP div support right away, and the code needs to be refactored
somewhat since the FPdiv pipe code is currently generic over being
16/32/64-bit at compile-time and the new code will need to be able to
dynamically switch between them at runtime, once FP is added again.

Luke, or whoever's available, can you give me an example of a
combinatorial stage chain that is used inside a single stage without
being wired as the inputs and outputs, along with getting all the
pipekls stuff connected properly?

Somewhat unrelated, I moved all the unused code out of the fpdiv
folder and into the unused folder

Jacob