Move writeOutline() and writeProgram() out of KernelTarget.

pkg/front_end/lib/src/fasta/kernel/utils.dart

Index: pkg/front_end/lib/src/fasta/kernel/utils.dart
diff --git a/pkg/front_end/lib/src/fasta/kernel/utils.dart b/pkg/front_end/lib/src/fasta/kernel/utils.dart
index 6748f99a01758c06ff26ea507cfd5e6bf3308725..9bb7a2f014b58c0ead18ad68795e56f1a054321e 100644
--- a/pkg/front_end/lib/src/fasta/kernel/utils.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/utils.dart
@@ -2,8 +2,12 @@
 // 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 'dart:io';
+
 import 'package:front_end/src/scanner/token.dart' show Token;
 import 'package:kernel/ast.dart';
+import 'package:kernel/binary/ast_to_binary.dart';
 import 'package:kernel/text/ast_to_text.dart';
 
 /// A null-aware alternative to `token.offset`.  If [token] is `null`, returns
@@ -21,3 +25,14 @@ void printProgramText(Program program) {
   }
   print(sb);
 }
+
+Future<Null> writeProgramToFile(Program program, Uri uri) async {
+  File output = new File.fromUri(uri);
+  IOSink sink = output.openWrite();
+  try {
+    new BinaryPrinter(sink).writeProgramFile(program);
+    program.unbindCanonicalNames();
+  } finally {
+    await sink.close();
+  }
+}