Add kernel/closed_world2_test

pkg/compiler/lib/src/ssa/kernel_impact.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 'package:kernel/ast.dart' as ir;
 
 import '../common.dart';
 import '../common/names.dart';
 import '../compiler.dart';
 import '../constants/expressions.dart';
 import '../common_elements.dart';
 import '../elements/types.dart';
 import '../elements/elements.dart' show AstElement, ResolvedAst;
 import '../elements/entities.dart';
 import '../js_backend/backend.dart' show JavaScriptBackend;
 import '../kernel/element_adapter.dart';
 import '../kernel/kernel.dart';
-import '../kernel/kernel_debug.dart';
 import '../resolution/registry.dart' show ResolutionWorldImpactBuilder;
 import '../universe/call_structure.dart';
 import '../universe/feature.dart';
 import '../universe/selector.dart';
 import '../universe/use.dart';
 
 import 'kernel_ast_adapter.dart';
 import '../common/resolution.dart';
 
 /// Computes the [ResolutionImpact] for [resolvedAst] through kernel.
@@ skipping 545 matching lines @@
     ConstructorEntity target = elementAdapter.getConstructor(node.target);
     impactBuilder.registerStaticUse(new StaticUse.superConstructorInvoke(
         target, elementAdapter.getCallStructure(node.arguments)));
   }
 
   // TODO(johnniwinther): Make this throw and visit child nodes explicitly
   // instead to ensure that we don't visit unwanted parts of the ir.
   @override
   void defaultNode(ir.Node node) => node.visitChildren(this);
 }