Add FrontEndStrategy, ResolutionFrontEndStrategy and KernelFrontEndStrategy

tests/compiler/dart2js/kernel/closed_world2_test.dart

 // Copyright (c) 2017, 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.
 
 // Partial test that the closed world computed from [WorldImpact]s derived from
 // kernel is equivalent to the original computed from resolution.
 library dart2js.kernel.closed_world2_test;
 
 import 'package:async_helper/async_helper.dart';
 import 'package:compiler/src/closure.dart';
@@ skipping 78 matching lines @@
         memorySourceFiles: memorySourceFiles,
         options: [
           Flags.analyzeAll,
           Flags.useKernel,
           Flags.enableAssertMessage
         ]);
     await compiler.run(entryPoint);
     compiler.resolutionWorldBuilder.closeWorld();
 
     print('---- closed world from kernel ------------------------------------');
-    KernelWorldBuilder worldBuilder = new KernelWorldBuilder(
-        compiler.reporter, compiler.backend.kernelTask.program);
+    KernelWorldBuilder worldBuilder = new KernelWorldBuilder(compiler.reporter);
+    worldBuilder.addProgram(compiler.backend.kernelTask.program);
     KernelEquivalence equivalence = new KernelEquivalence(worldBuilder);
     NativeBasicData nativeBasicData = computeNativeBasicData(worldBuilder);
     checkNativeBasicData(
         compiler.backend.nativeBasicData, nativeBasicData, equivalence);
     List list = createKernelResolutionEnqueuerListener(
         compiler.options,
         compiler.reporter,
         compiler.deferredLoadTask,
         worldBuilder,
         nativeBasicData);
@@ skipping 269 matching lines @@
       usage2.isInvokeOnUsed);
   check(usage1, usage2, 'isRuntimeTypeUsed', usage1.isRuntimeTypeUsed,
       usage2.isRuntimeTypeUsed);
   check(usage1, usage2, 'isIsolateInUse', usage1.isIsolateInUse,
       usage2.isIsolateInUse);
   check(usage1, usage2, 'isFunctionApplyUsed', usage1.isFunctionApplyUsed,
       usage2.isFunctionApplyUsed);
   check(usage1, usage2, 'isNoSuchMethodUsed', usage1.isNoSuchMethodUsed,
       usage2.isNoSuchMethodUsed);
 }