host/chez/dynamic-vars.ss binds the two seed-native dynamic vars that aren't
emitted into the prelude: *clojure-version* (the {:major 1 :minor 11 ...} map) and
*unchecked-math* (false). Removes their two run-corpus-prelude allowlist entries
(now 11, all passing).
*ns* is deferred to jolt-b4kl: it needs a namespace value that is not a map yet
answers (get ns :name) for the overlay ns-name, plus str/find-ns support.
Parity 1530 -> 1532/2497, 0 new divergences. emit-test 305/305.
d7420deecb