anchor.diff:      typeVariableHandler = new TypeVariableHandler(this);
       customElementsAnalysis = new CustomElementsAnalysis(this);
       constantCompilerTask = new JavaScriptConstantTask(compiler);
  -    resolutionCallbacks = new JavaScriptionResolutionCallbacks(this);
  +    resolutionCallbacks = new JavaScriptResolutionCallbacks(this);
     }
   
     ConstantSystem get constantSystem => constants.constantSystem;
  
positive.code:   }
  }
  
  class JavaScriptionResolutionCallbacks extends ResolutionCallbacks {
    final JavaScriptBackend backend;
  
    JavaScriptionResolutionCallbacks(this.backend);
  
    void registerBackendStaticInvocation(Element element, Registry registry) {
      registry.registerStaticInvocation(backend.registerBackendUse(element));
  
negative.code: 
    JavaScriptConstantTask constantCompilerTask;
  
    JavaScriptResolutionCallbacks resolutionCallbacks;
  
    JavaScriptBackend(Compiler compiler, bool generateSourceMap)
        : namer = determineNamer(compiler),
  