Run core.memoize's test suite on jolt

Shaking out clojure.core.memoize (207 assertions, 0 fail) cleared several
general gaps:

- deref/@ on a deftype or reify implementing clojure.lang.IDeref dispatches to
  its deref method (RetryingDelay / make-derefable).
- deftype mutable fields (^:unsynchronized-mutable / ^:volatile-mutable) are
  read live: a set! within a method is observed by a later read in the same
  invocation, not the entry-time capture. Needed for double-checked locking.
  Immutable fields stay let-bound. Field reads rewrite to (.-field inst) with
  lexical-shadow tracking.
- def metadata values are evaluated, like Clojure: ^{:k (f)} stores (f)'s
  result and ^{:af some-fn} the fn. :tag stays a literal hint.
- try dispatches catch clauses by class in order via the exception supertype
  hierarchy; a non-matching value re-throws, an untyped host condition is caught
  by a RuntimeException/Exception/Throwable clause. Previously the last clause
  won and the class was ignored.
- locking takes a real per-object monitor (recursive Chez mutex) now that
  futures/agents/threads share one heap; it was a no-op.
- supers/ancestors reflect a small modeled JVM interface hierarchy, so
  (ancestors (class f)) yields Runnable/Callable (core.memoize's arg check).
- AssertionError / Error constructors.

JOLT_FEATURES is gone from the docs: it isn't read anywhere on Chez, and the
reader already includes :clj in its default feature set. RFC 0002's
{:jolt :default} design was reverted in the reader; docs now match the code.

Raises the SCI floor 205 -> 210.

jolt-core/clojure/core/20-coll.clj

@@ -311,7 +311,12 @@
 
 (defn ancestors
   ([tag] (ancestors (deref global-hierarchy) tag))
-  ([h tag] (not-empty (get (get h :ancestors) tag))))
+  ([h tag]
+   ;; the user hierarchy plus any modeled JVM ancestry (jolt.host/class-ancestors)
+   ;; so (ancestors (class x)) answers like the JVM for the common interfaces.
+   (let [hier (get (get h :ancestors) tag)
+         host (jolt.host/class-ancestors tag)]
+     (not-empty (if host (into (or hier #{}) host) hier)))))
 
 (defn descendants
   ([tag] (descendants (deref global-hierarchy) tag))