and bring in the :rzero code and the new instruction macro
start restructuring the ISA definition and using :require instead of :use
ditch '0' and 'nil' as valid registers, add opcode verification code
rework to use :require instead of :use and appropriate symbol name changes
looks like the symbol resolution changes didn't get flushed before that last commit
finish the namespace changes, now issues with instruction representation
update for new internal instruction representation
reset stages all the way back to the last stable
patch fetch for improved readability, use .isa not .util
a more idiomatic apply-times, a diff wrapper and forgot the :fpc key leading to null issues in fetch
restructure the ISA in a more modular fassion, add some macros and a defrecord to clean stuff up
add a nice remove-once, and clean initial-state to reflect new register defs
a shitload of work in the direction of moving from vectors to structured maps, intermediate work to the new Opcode record type