support unparsing of "new Object()":

lib/compiler/implementation/dart_backend/backend.dart

Index: lib/compiler/implementation/dart_backend/backend.dart
diff --git a/lib/compiler/implementation/dart_backend/backend.dart b/lib/compiler/implementation/dart_backend/backend.dart
index b03c108c4204ee3cf76c583321093b9c8c1ec910..86cc25a536f3e799900eef27c929b363752d6220 100644
--- a/lib/compiler/implementation/dart_backend/backend.dart
+++ b/lib/compiler/implementation/dart_backend/backend.dart
@@ -42,9 +42,28 @@ class DartBackend extends Backend {
       throw new BailoutException(reason);
     }
 
+    /**
+     * Tells whether we should output given element. Corelib classes like
+     * Object should not be in the resulting code.
+     */
+    bool shouldOutput(Element element) {
+      var compilationUnitUri = element.getCompilationUnit().script.uri;
+      if (compilationUnitUri !== null && compilationUnitUri.path !== null &&

[Anton Muhin, 2012/07/09 18:31:26]

I believe (but not 100% sure) that we have a references to core lib and some
other standard libs, cannot you just do === check on it?

[Roman, 2012/07/10 03:20:29]

Done.
Thanks! Indeed we have reference in compiler. I just grepped for corelib and
found some hacks like mine in tests, that confused me.

+          // TODO(smok): URI hacks, should we have a special 'core' flag for
+          // elements from corelib?
+          (compilationUnitUri.path.endsWith('/core.dart')
+              || compilationUnitUri.path.contains('/corelib/src/'))) {
+        return false;
+      }
+      return element.kind !== ElementKind.VOID;
+    }
+
     try {
       StringBuffer sb = new StringBuffer();
       resolvedElements.forEach((element, treeElements) {
+        if (!shouldOutput(element)) {

[Anton Muhin, 2012/07/09 18:31:26]

nit: single line.

[Roman, 2012/07/10 03:20:29]

Done.

+          return;
+        }
         if (!element.isTopLevel()) {
           bailout('Cannot process non top-level $element');
         }