jolt fns reported (class f) = clojure.lang.IFn, so they carried no defining
symbol — clojure.spec.alpha's fn-sym (which reads a fn's class name to recover its
symbol) produced garbage, so explain-data's :pred for a bare-fn predicate was `/`
instead of e.g. clojure.core/keyword?.
Now def-var! records proc -> (ns . name) (first def of a proc wins, so an alias
like (def inc' inc) doesn't rename inc), and jolt-class-name returns "ns$munged"
for a known fn — matching the JVM, where (class odd?) is clojure.core$odd_QMARK_.
A munged fn class's ancestors include clojure.lang.AFunction's hierarchy
(IFn/AFn/Fn/Runnable/Callable), so (ancestors (class f)) still holds. Anonymous /
unregistered fns stay clojure.lang.IFn (fn-sym yields :unknown, as on the JVM).
This fixes explain-data / s/form / s/describe of bare-fn predicates in
clojure.spec.alpha (and unblocks parts of its suite + test.check's reporter test).
make test green (+1 corpus row, the (type inc) unit row updated to the JVM value),
shakesmoke byte-identical, runtime only (no re-mint).