Use backend targets to run Kernel transformations in Fasta

pkg/front_end/test/fasta/shaker_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.md file.
 
 /// Tests basic functionality of the API tree-shaker.
 ///
 /// Each input file is built and tree-shaken, then we check that the set of
 /// libraries, classes, and members that are retained match those declared in an
 /// expectations file.
 ///
@@ skipping 77 matching lines @@
 class BuildProgram
     extends Step<TestDescription, _IntermediateData, TreeShakerContext> {
   const BuildProgram();
   String get name => "build program";
   Future<Result<_IntermediateData>> run(
       TestDescription description, TreeShakerContext context) async {
     try {
       var platformOutline = context.loadPlatformOutline();
       platformOutline.unbindCanonicalNames();
       var dillTarget = new DillTarget(
-          new Ticker(isVerbose: false), context.uriTranslator, "vm");
+          new Ticker(isVerbose: false), context.uriTranslator, "vm_fasta");
       dillTarget.loader.appendLibraries(platformOutline);
       var sourceTarget = new KernelTarget(PhysicalFileSystem.instance,
           dillTarget, context.uriTranslator, false);
       await dillTarget.buildOutlines();
 
       var inputUri = description.uri;
 
       /// We treat the lib.dart library as a special dependency that was
       /// previously built. To do so, we build it and append it back to the
       /// dillTarget before building the actual test.
@@ skipping 123 matching lines @@
           """
 Please create file ${expectedFile.path} with this content:
 $buffer""");
     }
   }
 }
 
 /// A special library used only to test the shaker. The suite above will
 /// tree-shake the contents of this library.
 const _specialLibraryPath = 'pkg/front_end/testcases/shaker/lib/lib.dart';