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.

docs/spec/02-reader.md

@@ -159,9 +159,10 @@ checks → UNVERIFIED (rows to add).
   key the platform satisfies wins (`#?(:default 5 :clj 6)` is `5` everywhere)
   — not by key priority. Implementations SHOULD provide a per-loading-context
   compatibility override for foreign-dialect libraries. (jolt:
-  `#{:jolt :default}`, opt-in via `reader-features-set!`/`JOLT_FEATURES`;
-  decision + A/B data in RFC 0002 — inheriting `:clj` cost 146 suite
-  assertions and 38 errors.)
+  `#{:jolt :clj :default}` — jolt emulates `clojure.lang.*`/`java.*`, so it
+  reads the `:clj` branch of a `.cljc` library by default; a library can put a
+  `:jolt` branch first to override, or a loading context can call
+  `reader-features-set!`. History in RFC 0002.)
 - Reader conditionals MUST be an error outside `.cljc`-style reading unless
   the implementation documents otherwise.