7. Platform ABI declarations - deferred with a condition

Several hundred function signatures, declared in a probe to be called and implemented in an emulator to be provided. They can disagree about an arity today, which is worse than the magic bug: a wrong arity corrupts a stack and faults somewhere unrelated to the cause.

Deferred rather than forgotten, because the two consumers hold the same facts to deliberately different standards. A shared set has to carry the provenance level with each signature. (D003)