Change all File APIs to make the mode and encoding arguments named

sdk/lib/_internal/compiler/implementation/dart2js.dart

 // Copyright (c) 2013, 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 dart2js;
 
 import 'dart:async';
 import 'dart:collection' show Queue, LinkedHashMap;
 import 'dart:io';
 import 'dart:uri';
@@ skipping 327 matching lines @@
 class AbortLeg {
   final message;
   AbortLeg(this.message);
   toString() => 'Aborted due to --throw-on-error: $message';
 }
 
 void writeString(Uri uri, String text) {
   if (uri.scheme != 'file') {
     fail('Error: Unhandled scheme ${uri.scheme}.');
   }
-  var file = new File(uriPathToNative(uri.path)).openSync(FileMode.WRITE);
+  var file = new File(uriPathToNative(uri.path)).openSync(mode: FileMode.WRITE);
   file.writeStringSync(text);
   file.closeSync();
 }
 
 void fail(String message) {
   print(message);
   exit(1);
 }
 
 void compilerMain(Options options) {
@@ skipping 137 matching lines @@
     } catch (ignored) {
       print('Internal error: error while printing exception');
     }
     try {
       print(trace);
     } finally {
       exit(253); // 253 is recognized as a crash by our test scripts.
     }
   }
 }