Report messages instead of just printing.

pkg/front_end/lib/src/fasta/target_implementation.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.
 
 library fasta.target_implementation;
 
 import 'package:kernel/target/targets.dart' as backend show Target;
 
 import 'builder/builder.dart' show Builder, ClassBuilder, LibraryBuilder;
 
+import 'compiler_context.dart' show CompilerContext;
+
 import 'loader.dart' show Loader;
 
 import 'target.dart' show Target;
 
 import 'ticker.dart' show Ticker;
 
 import 'uri_translator.dart' show UriTranslator;
 
 /// Provides the implementation details used by a loader for a target.
 abstract class TargetImplementation extends Target {
   final UriTranslator uriTranslator;
 
   final backend.Target backendTarget;
 
+  final CompilerContext context = CompilerContext.current;
+
   Builder cachedAbstractClassInstantiationError;
   Builder cachedCompileTimeError;
   Builder cachedDuplicatedFieldInitializerError;
   Builder cachedFallThroughError;
   Builder cachedNativeAnnotation;
 
   TargetImplementation(Ticker ticker, this.uriTranslator, this.backendTarget)
       : super(ticker);
 
   /// Creates a [LibraryBuilder] corresponding to [uri], if one doesn't exist
@@ skipping 67 matching lines @@
   void readPatchFiles(LibraryBuilder library) {
     assert(library.uri.scheme == "dart");
     List<Uri> patches = uriTranslator.getDartPatches(library.uri.path);
     if (patches != null) {
       for (Uri patch in patches) {
         library.loader.read(patch, -1, fileUri: patch, isPatch: true);
       }
     }
   }
 }