when i omit the instructions which assume the existence of a heap allocator and the affordances one permits, the birch instruction set is down to 40. i'm purposefully avoiding looking at Uxn too closely apart from superficial matters because i really do want birch to be its own thing, but, that's just 8 more than Uxn, with some support for quickly addressing stack locals across frames and other things that truly make sense to consolidate into discrete instructions.

i'm fairly happy with this.