Two general fixes shaken out by core.typed's runtime contract suite

Running clojure.core.typed's runtime contract tests (typed/runtime.jvm,
test_contract — 5/5 pass) surfaced two general jolt gaps, both runtime, both
JVM-certified:

- instance? Object / java.lang.Object returned false for everything. Object is
  the root of the type hierarchy: every non-nil value is an instance of Object,
  nil is not. core.typed's (instance-c Object) contract depends on this; many
  libraries do.
- @Compiler/LINE and @Compiler/COLUMN (clojure.lang.Compiler statics — Vars on
  the JVM holding the line/column of the form being compiled) were unresolved.
  Macros read @Compiler/LINE as a fallback when &form carries no position. Now
  backed by derefable cells updated per top-level form, like *current-source*.

The core.typed type checker itself (tools.analyzer.jvm + ASM bytecode +
clojure.lang.Compiler internals) and the cljs runtime are not portable, so the
checker/check-ns surface is out of scope; this is the runtime contract layer.

make test green (+4 corpus rows, 0 new divergences), shakesmoke byte-identical.

host/chez/java/records-interop.ss

@@ -87,6 +87,15 @@
     (let ((k (chez-condition-exc-class val)))
       (if k (if (exception-isa? k (last-dot (symbol-t-name type-sym))) #t #f) 'pass))))
 
+;; Object / java.lang.Object is the root of the type hierarchy: every non-nil
+;; value is an instance of Object; nil is not an instance of anything.
+(register-instance-check-arm!
+  (lambda (type-sym val)
+    (let ((tn (symbol-t-name type-sym)))
+      (if (or (string=? tn "Object") (string=? tn "java.lang.Object"))
+          (not (jolt-nil? val))
+          'pass))))
+
 (define (instance-check-base type-sym val)
   (let ((tname (symbol-t-name type-sym)))
     (cond