jolt-get (4 sites: host-table/natives-misc/inst-time/records) and jolt=2 (6 sites:
records/vars/inst-time/natives-misc/bigdec/host-table) move off the set!-rebind
chains to register-get-arm! / register-eq-arm!. get's case-lambda becomes a stable
2/3-arg entry over a 3-arg dispatch; the equality arm pred is (a b) since either arg
may carry the type, and the host-table sorted arm normalizes-then-re-dispatches.
Behaviour-preserving (runtime .ss): var/inst/bigdec/record/uuid equality, record!=map,
sorted-map=plain-map, and all the get cases verified; make test green, 0 new corpus
divergences. Four of six dispatchers done; the printer (pr-str/pr-readable) remains.