Cache output of dart2js compilations that went wrong on disk.

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.cmdline;
 
 import 'dart:async'
     show Future, EventSink;
 import 'dart:io'
     show exit, File, FileMode, Platform, RandomAccessFile, FileSystemException;
@@ skipping 347 matching lines @@
 
   int totalCharactersWritten = 0;
 
   options.add('--out=$out');
   options.add('--source-map=$sourceMapOut');
 
   List<String> allOutputFiles = new List<String>();
 
   compilationDone(String code) {
     if (analyzeOnly) return;
+    writeString(Uri.parse('$out.deps'),
+                getDepsOutput(inputProvider.sourceFiles));
     if (code == null) {
       fail('Compilation failed.');
     }
-    writeString(Uri.parse('$out.deps'),
-                getDepsOutput(inputProvider.sourceFiles));
     diagnosticHandler.info(
          'Compiled ${inputProvider.dartCharactersRead} characters Dart '
          '-> $totalCharactersWritten characters $outputLanguage '
          'in ${relativize(currentDirectory, out, isWindows)}');
     if (diagnosticHandler.verbose) {
       String input = uriPathToNative(arguments[0]);
       print('Dart file ($input) compiled to $outputLanguage.');
       print('Wrote the following files:');
       for (String filename in allOutputFiles) {
         print("  $filename");
@@ skipping 280 matching lines @@
     }
   }
 
   try {
     return compilerMain(arguments).catchError(onError);
   } catch (exception, trace) {
     onError(exception, trace);
     return new Future.value();
   }
 }