Avoid crashing on function syntax.

tools/patch_sdk.dart

 #!/usr/bin/env dart
 // Copyright (c) 2015, 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.
 
 /// Command line tool to merge the SDK libraries and our patch files.
 /// This is currently designed as an offline tool, but we could automate it.
 
 import 'dart:io';
 import 'dart:async';
@@ skipping 60 matching lines @@
 
   var mode = argv[0];
   assert(mode == "vm");
   var input = argv[1];
   var sdkLibIn = path.join(input, 'lib');
   var patchIn = argv[2];
   var outDir = argv[3];
   var sdkOut = path.join(outDir, 'lib');
   var packagesFile = argv[4];
 
-  var privateIn = path.join(input, 'private');
-  var INTERNAL_PATH = '_internal/compiler/js_lib/';
-
   // Copy and patch libraries.dart and version
   var libContents = readInputFile(path.join(
       sdkLibIn, '_internal', 'sdk_library_metadata', 'lib', 'libraries.dart'));
   libContents = libContents.replaceAll(
       ' libraries = const {',
       ''' libraries = const {
 
   "_builtin": const LibraryInfo(
       "_builtin/_builtin.dart",
       categories: "Client,Server",
@@ skipping 513 matching lines @@
     if (diff != 0) return diff;
     return end - other.end;
   }
 }
 
 List<SdkLibrary> _getSdkLibraries(String contents) {
   var libraryBuilder = new SdkLibrariesReader_LibraryBuilder(true);
   parseCompilationUnit(contents).accept(libraryBuilder);
   return libraryBuilder.librariesMap.sdkLibraries;
 }