Pass backend Target into Kernel driver.

pkg/front_end/lib/src/incremental_kernel_generator_impl.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.
 
 import 'dart:async';
 
 import 'package:front_end/incremental_kernel_generator.dart';
 import 'package:front_end/src/base/performace_logger.dart';
 import 'package:front_end/src/base/processed_options.dart';
 import 'package:front_end/src/fasta/uri_translator.dart';
 import 'package:front_end/src/incremental/file_state.dart';
 import 'package:front_end/src/incremental/kernel_driver.dart';
 import 'package:kernel/kernel.dart' hide Source;
+import 'package:kernel/target/targets.dart';
+import 'package:kernel/target/vm_fasta.dart';
 import 'package:meta/meta.dart';
 
 /// Implementation of [IncrementalKernelGenerator].
 ///
 /// TODO(scheglov) Update the documentation.
 ///
 /// Theory of operation: an instance of [IncrementalResolvedAstGenerator] is
 /// used to obtain resolved ASTs, and these are fed into kernel code generation
 /// logic.
 class IncrementalKernelGeneratorImpl implements IncrementalKernelGenerator {
@@ skipping 25 matching lines @@
         _watchFn = watch {
     _testView = new _TestView(this);
 
     Future<Null> onFileAdded(Uri uri) {
       if (_watchFn != null) {
         return _watchFn(uri, true);
       }
       return new Future.value();
     }
 
-    _driver = new KernelDriver(_logger, options.fileSystem, options.byteStore,
-        uriTranslator, options.strongMode,
+    _driver = new KernelDriver(
+        _logger,
+        options.fileSystem,
+        options.byteStore,
+        uriTranslator,
+        new VmFastaTarget(new TargetFlags(strongMode: options.strongMode)),
         fileAddedFn: onFileAdded);
   }
 
   /// Return the object that provides additional information for tests.
   @visibleForTesting
   _TestView get test => _testView;
 
   @override
   Future<DeltaProgram> computeDelta() async {
     return await _logger.runAsync('Compute delta', () async {
@@ skipping 78 matching lines @@
 
 @visibleForTesting
 class _TestView {
   final IncrementalKernelGeneratorImpl _generator;
 
   _TestView(this._generator);
 
   /// The [KernelDriver] that is used to actually compile.
   KernelDriver get driver => _generator._driver;
 }