Make clojure.spec.alpha load and run

Four general gaps, shaken out by loading clojure.spec.alpha:

- Special forms were shadowable by a same-named macro. analyze-list
  macroexpanded before checking special forms, so a ns that redefs def/and/or
  (spec excludes them via :refer-clojure :exclude) made a bare def resolve to
  the macro instead of the special form, breaking every defn after. Now a head
  in the special-form set is never macroexpanded, matching the reference
  macroexpand1 isSpecial check.

- reify dropped all but the last arity of a multi-arity protocol method (spec
  reifies (specize* [s]) and (specize* [s _])). The macro keyed methods by name
  and overwrote; now it groups arities into one multi-arity fn.

- reify instances did not implement IObj: with-meta threw and (instance?
  clojure.lang.IObj r) was false. Every Clojure reify carries metadata. with-meta
  now copies the reify to a fresh identity (shared method table) and keys its
  meta; instance? IObj/IMeta is true for any reify. This was the registry bug —
  spec's with-name returned nil for specs, so get-spec missed.

- (set! (. Class field) val) was rejected. spec toggles
  clojure.lang.RT/checkSpecAsserts this way; the analyzer now lowers it to a
  jolt.host/set-static-field! call over a mutable-statics table, and a plain
  Class/field read consults that table.

Also: .name/.getName on a Namespace and .ns/.sym on a Var (spec's ns-qualify /
->sym). analyzer + reify are seed sources (re-minted). spec.alpha now does
valid?/conform/cat/keys/explain-str/check-asserts. tick.alpha.interval-test still
needs time-literals data readers (separate).

host/chez/records-interop.ss

@@ -68,7 +68,9 @@
              (and (> (string-length tag) (string-length tname))
                   (string=? (substring tag (- (string-length tag) (string-length tname)) (string-length tag)) tname)))))
       ((jreify? val) (let ((short (last-dot tname)))
-                       (and (memp (lambda (p) (string=? (last-dot p) short)) (jreify-protos val)) #t)))
+                       ;; every Clojure reify implements IObj/IMeta (carries metadata).
+                       (or (member short '("IObj" "IMeta"))
+                           (and (memp (lambda (p) (string=? (last-dot p) short)) (jreify-protos val)) #t))))
       ((ex-info-map? val) (exception-isa? (last-dot (ex-info-class val)) (last-dot tname)))
       (else (case-string tname val)))))