fp: decided that FP will happen in same unit type as the multiplier
opa: reorganize arbitration to save 2 levels of logic when window=12+4
syn: tweaked testbench to remove bypassed M9K => was slowing down design
regfile: can use r_map, as it is only out-of-date when we bypass anyway

Need to improve timing here.
It is now the critical path... AND I want to shave off 1-pipeline stage.
That's going to take some work!