General fixes shaken out by clojure/tools.reader

Running clojure.tools.reader's own suite on jolt surfaced a batch of general
gaps (all runtime, JVM-certified, no re-mint — reader.ss is loaded at runtime
and jolt-core has no octal literals, so selfhost holds):

Reader:
- (load "rel") resolves a non-/ path against the current namespace's directory,
  like Clojure — (load "common_tests") from clojure.tools.reader-test loads
  clojure/tools/common_tests.clj. Was resolved against the roots directly.
- Octal integer literals: 042 reads as 34, not decimal 42; octal string escapes
  (\377 is one char, not \0 + "00"). \oNNN char octal already worked.
- (symbol nil name) now equals (symbol name) and the reader literal — a nil
  namespace is the #f no-ns sentinel, not jolt-nil (jolt= compares ns by equal?).

clojure.test:
- thrown-with-msg? honors the class hierarchy (instance?) before falling back to
  a simple-name match, so (thrown-with-msg? RuntimeException ...) matches an
  ExceptionInfo, like thrown? already did.

Host interop (java layer):
- java.util.regex: Pattern.matcher / Matcher.matches / .group / .groupCount /
  .find, and Pattern/compile.
- clojure.lang: RT/map, PersistentList/create, PersistentHashSet/createWithCheck.
- java.lang.Character: digit / isDigit / isWhitespace / valueOf.
- java.util.LinkedList (Deque surface over the ArrayList backing); ArrayList /
  LinkedList are now seqable.
- BigInteger 2-arg ctor (string, radix) + .negate / .bitLength / .signum / .abs;
  BigInt/fromBigInteger and Numbers/reduceBigInt (identity on jolt's exact ints).

Suite: reader_test 22/30, reader-edn_test 13/16. The remaining failures are
fundamental numeric-model differences (no BigDecimal type; BigInt and Long are
one exact-integer type) or need JVM reflection (record/ctor tagged literals via
getConstructors) — out of scope.

make test green (+8 corpus rows, 0 new divergences), shakesmoke byte-identical.

stdlib/clojure/test.clj

@@ -107,7 +107,8 @@
 
      ;; (is (thrown-with-msg? Class re body...))
      (thrown-form? form "thrown-with-msg?")
-     (let [klass (name (second form))
+     (let [klass-sym (second form)
+           klass (name klass-sym)
            re    (nth form 2)
            body  (nthrest form 3)]
        `(try
@@ -115,7 +116,11 @@
           (clojure.test/fail! (str "expected " '~form " to throw"))
           (catch Throwable e#
             (let [m# (or (clojure.core/ex-message e#) (str e#))]
-              (if (and (clojure.test/class-match? e# ~klass) (re-find ~re m#))
+              ;; honor the class hierarchy (ExceptionInfo IS a RuntimeException),
+              ;; then fall back to a simple-name match like thrown? does.
+              (if (and (or (clojure.core/instance? ~klass-sym e#)
+                           (clojure.test/class-match? e# ~klass))
+                       (re-find ~re m#))
                 (clojure.test/inc-pass!)
                 (clojure.test/fail! (str "expected throw of " ~klass " matching " ~re " but got " (clojure.core/class e#) ": " m#)))))))