Faster Testing for BSV Simulation

[dz333]

The pipedsl.RiscSuite runs a bunch of different RISC-V pipelines on several different programs.
Currently the suite recompiles each pipeline once for each program - this is very unnecessary and slow.

Ideally, we should just generate the code once and then copy in different memory files- we don't do this right now b/c the compiler itself has convenience functionality for copying memory files as it generates code.