anchor.diff:        FunctionSignature functionSignature = body.computeSignature(compiler);
         int arity = functionSignature.parameterCount;
         functionSignature.orderedForEachParameter((parameter) {
  -        // TODO(ngeoffray): No need to pass the parameters that are
  -        // captured and stored in a box. Because this information is
  -        // not trivial to get in codegen.dart, we just pass the
  -        // parameters anyway. We need to update both codegen.dart and
  -        // builder.dart on how parameters are being passed.
  -        bodyCallInputs.add(localsHandler.readLocal(parameter));
  +        if (!localsHandler.isBoxed(parameter)) {
  +          // The parameter will be a field in the box passed as the
  +          // last parameter. So no need to pass it.
  +          bodyCallInputs.add(localsHandler.readLocal(parameter));
  +        }
         });
   
         // If parameters are checked, we pass the already computed
  
positive.code:       FunctionElement functionElement = element;
        FunctionSignature params = functionElement.computeSignature(compiler);
        params.orderedForEachParameter((Element parameterElement) {
          HInstruction parameter = builder.addParameter(parameterElement);
          builder.parameters[parameterElement] = parameter;
          directLocals[parameterElement] = parameter;
  
negative.code:       scopeData.capturedVariableMapping.forEach((Element from, Element to) {
          // The [from] can only be a parameter for function-scopes and not
          // loop scopes.
          if (from.isParameter() && !element.isGenerativeConstructorBody()) {
            // Now that the redirection is set up, the update to the local will
            // write the parameter value into the box.
            // Store the captured parameter in the box. Get the current value
            // before we put the redirection in place.
            // We don't need to update the local for a generative
            // constructor body, because it receives a box that already
            // contains the updates as the last parameter.
            HInstruction instruction = readLocal(from);
            redirectElement(from, to);
            updateLocal(from, instruction);
          } else {
            redirectElement(from, to);
  