Realization.Nvidia.SM86.StallCompaction

A PROPOSER, not part of any argument: it rewrites a program's stall counts to the smallest each instruction's successor allows, by the same accounting SM86.Scoreboard's fixed-latency pass checks (issue one instruction, wait its stall; a fixed-latency result is ready sm86FixedLatency cycles after issue, a barrier sm86BarrierSetCycles after the instruction that sets it). Whatever it proposes is accepted only if the checker accepts it (SM86.LinearStepCheck.linearStepProgramAcceptedWith for the linear step); a mistake here is a rejected proposal, never a wrong program. Generated programs stall 15 cycles after every instruction (the maximum, chosen when nothing modelled latency); most instructions need 1, none less than its sm86MinimumStall. The annotated program: each instruction's schedule keys computed once. The old walk eliminated every body five times per step -- writes, latency and set keys for the issue at this step, reads, writes, guard, predicate and wait keys for the need of the previous one -- and rebuilt each instruction with a sixth split. Annotation does one 37-branch split per instruction up front (each field the same branch body the old helpers used), and carries the keys forward with the instruction itself, so the walk never re-examines a body except to rebuild it with its new stall.

40field unrestricted compactionAnnotatedMinimumStall : Nat