[libre-riscv-dev] minerva nmigen code

[Luke Kenneth Casson Leighton]

https://github.com/lambdaconcept/minerva/blob/master/minerva/units/loadstore.py

all of this looks *really* good, very clear, very obvious what's going
on: my feeling is, we should just adopt it and save a whole boat-load
of time.

when it comes to SMP it will need some adaptation, however we can deal
with that when the time comes.

i particularly like that it's integrated with wishbone already.

l.