Factored the generation of JSON serialization from beeing part of the mirror ...

test/mjsunit/mirror-object.js

Index: test/mjsunit/mirror-object.js
===================================================================
--- test/mjsunit/mirror-object.js	(revision 1024)
+++ test/mjsunit/mirror-object.js	(working copy)
@@ -119,7 +119,7 @@
         found = true;
       }
     }
-    assertTrue(found, '"' + name + '" not found');
+    assertTrue(found, '"' + name + '" not found (' + json + ')');
   }
 }
 
@@ -139,6 +139,11 @@
 testObjectMirror([], 'Array', 'Array');
 testObjectMirror([1,2], 'Array', 'Array');
 
+// Test circular references.
+o = {};
+o.o = o;
+testObjectMirror(o, 'Object', 'Object');
+
 // Test that non enumerable properties are part of the mirror
 global_mirror = debug.MakeMirror(this);
 assertEquals('property', global_mirror.property("Math").type());