Fix redness in bot

pkg/compiler/lib/src/ssa/builder_kernel.dart

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 import '../common/codegen.dart' show CodegenWorkItem;
 import '../common/tasks.dart' show CompilerTask;
 import '../io/source_information.dart';
 import '../js_backend/backend.dart' show JavaScriptBackend, FunctionCompiler;
 import '../elements/elements.dart';
 
 import 'nodes.dart';
 
 class SsaKernelBuilderTask extends CompilerTask {
   final JavaScriptBackend backend;
   final SourceInformationStrategy sourceInformationFactory;
 
   String get name => 'SSA kernel builder';
 
   SsaKernelBuilderTask(JavaScriptBackend backend, this.sourceInformationFactory)
-      : super(backend.compiler.measurer);
+      : backend = backend,
+        super(backend.compiler.measurer);
 
   HGraph build(CodegenWorkItem work) {
     return measure(() {
       Element element = work.element.implementation;
       throw "unimplemented";
     });
   }
 }