anchor.diff:        }
       }
       log('Excess resolution work: ${resolved.length}.');
  -    if (!REPORT_EXCESS_RESOLUTION) return;
       for (Element e in resolved) {
         SourceSpan span = spanFromElement(e);
         reportDiagnostic(span, 'Warning: $e resolved but not compiled.',
  
positive.code:         internalErrorOnElement(work.element, "Work list is not empty.");
        });
      }
      var resolved = new Set.from(enqueuer.resolution.resolvedElements.keys);
      for (Element e in codegenWorld.generatedCode.keys) {
        resolved.remove(e);
  
negative.code:         new dart_backend.DartBackend(this, strips);
      constantHandler = new ConstantHandler(this, backend.constantSystem);
      enqueuer = new EnqueueTask(this);
      tasks = [scanner, dietParser, parser, patchParser, libraryLoader,
               resolver, closureToClassMapper, checker, typesTask,
               constantHandler, enqueuer];
      tasks.addAll(backend.tasks);
    }
  
  