Add FrontEndStrategy, ResolutionFrontEndStrategy and KernelFrontEndStrategy

tests/compiler/dart2js/kernel/closed_world2_test.dart

Index: tests/compiler/dart2js/kernel/closed_world2_test.dart
diff --git a/tests/compiler/dart2js/kernel/closed_world2_test.dart b/tests/compiler/dart2js/kernel/closed_world2_test.dart
index bcdfd52112cbcc7b5a499b0b4b6956808b0ae577..ca8e9ef22a02808d1f67a8712718ee000066ed37 100644
--- a/tests/compiler/dart2js/kernel/closed_world2_test.dart
+++ b/tests/compiler/dart2js/kernel/closed_world2_test.dart
@@ -96,8 +96,8 @@ main(List<String> args) {
     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(