spec.alpha: reify ILookup get, NPE/CCE, quoted #inst/#uuid, anon-fn class, kwargs map

Close clojure.spec.alpha's remaining gaps — its conform/explain/describe/multi-spec
suite (clojure.test-clojure.spec, multi-spec) now passes fully.

- (get reify k) / (:k reify) routes to a reify's clojure.lang.ILookup valAt. spec
  reifies fspec/regex specs as ILookup and reads (:args spec) off them, so before
  this instrument never saw the args spec.
- A failed numeric comparison reports the JVM class: a nil operand is
  NullPointerException, a non-number is ClassCastException (was an opaque :object
  condition). conform-explain checks the thrown class.
- A quoted / macro-form #inst / #uuid literal constructs its Date/UUID value, like
  the JVM reader (which builds it at read time). emit-quoted was emitting the raw
  tagged form, so #inst "1939" and #inst "1939-01-01T00:00:00.000-00:00" weren't =.
- An anonymous fn reports class clojure.lang.AFunction$fn (the $fn marker), so
  spec's fn-sym returns ::s/unknown for it, matching the JVM's ns$fn__N.
- A fn with & {:as m} kwargs accepts a trailing map (Clojure 1.11): (f :a 1 {:b 2})
  and (f {:a 1}) both bind m, by merging an odd trailing map over the pairs.
- A thread responds to .getStackTrace (empty — jolt does TCO).

clojure.test-clojure.instr does not fully pass: its ::caller assertions need the
calling fn's stack frame, which TCO erases (an inherent host divergence, like the
JVM keeping tail frames).

make test green (+4 corpus rows, 0 new divergences), shakesmoke byte-identical.
Re-mint (backend emit-quoted + the destructure macro).

host/chez/java/host-class.ss

@@ -35,7 +35,11 @@
     ((jolt-atom? x) "clojure.lang.Atom")
     ((char? x) "java.lang.Character")
     ((regex-t? x) "java.util.regex.Pattern")
-    ((procedure? x) "clojure.lang.IFn")
+    ;; an anonymous / unregistered fn — like the JVM, where (class #(..)) is a
+    ;; concrete ns$fn__N subclass. The $fn marker lets clojure.spec.alpha's fn-sym
+    ;; recognize it as anonymous and return ::s/unknown. A named fn is registered
+    ;; (proc-name-tbl) and handled by a class-arm with its real ns$name.
+    ((procedure? x) "clojure.lang.AFunction$fn")
     ;; an exception value (ex-info / host-constructed throwable) reports its JVM
     ;; class, so (= clojure.lang.ExceptionInfo (class e)) and clojure.test's
     ;; (thrown? Class …) match (records.ss ex-info-map?/ex-info-class).
@@ -59,9 +63,8 @@
 ;; (thrown? ArityException …) test match — not the opaque :object fallback.
 (register-class-arm!
   (lambda (x) (and (chez-condition-exc-class x) #t))
-  (lambda (x) (if (string=? (chez-condition-exc-class x) "ArityException")
-                  "clojure.lang.ArityException"
-                  "java.lang.IllegalArgumentException")))
+  (lambda (x) (let ((p (assoc (chez-condition-exc-class x) class-token-alist)))
+                (if p (cdr p) "java.lang.IllegalArgumentException"))))
 ;; A fn def'd into a var reports a JVM-style class name "ns$munged-name" (the
 ;; forward CHAR_MAP), so clojure.spec.alpha's fn-sym (which splits on $ and
 ;; demunges) recovers the predicate's symbol. Anonymous / unregistered fns stay