Add support for compiling Dart via the FE in dart2js.

pkg/compiler/tool/perf.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.
 
 /// An entrypoint used to run portions of dart2js and measure its performance.
 library compiler.tool.perf;
 
 import 'dart:async';
 import 'dart:io';
 
@@ skipping 304 matching lines @@
   // TODO(sigmund): this is here only to compute the input size,
   // we should extract the input size from the frontend instead.
   scanReachableFiles(entryUri);
 
   var timer = new Stopwatch()..start();
   var options = new CompilerOptions(
       entryPoint: entryUri,
       libraryRoot: _libraryRoot,
       packagesDiscoveryProvider: findPackages,
       platformConfigUri: _platformConfigUri,
-      useKernel: true,
+      useKernelInSsa: true,
       verbose: false); // set to true to debug internal timings
   var inputProvider = new CompilerSourceFileProvider();
   var diagnosticHandler = new FormattingDiagnosticHandler(inputProvider)
     ..verbose = options.verbose;
   var compiler = new MyCompiler(inputProvider, diagnosticHandler, options);
   await compiler.run(entryUri);
   timer.stop();
   report('kernel_gen_e2e', timer.elapsedMicroseconds);
 }
 
@@ skipping 42 matching lines @@
           print('compilation failed!');
           exit(1);
         }
 
         backend.onResolutionEnd();
         closeResolution(mainFunction);
         var program = (backend as dynamic).kernelTask.program;
         print('total libraries: ${program.libraries.length}');
       });
 }