Use correct types on cloned constructors in mixin applications.

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 190 matching lines @@
     var builtinLibraryOut = path.join(sdkOut, vmLibrary, '${vmLibrary}.dart');
     _writeSync(builtinLibraryOut, readInputFile(builtinLibraryIn));
   }
 
   for (var file in ['loader.dart', 'server.dart', 'vmservice_io.dart']) {
     var libraryIn = path.join(dartDir, 'runtime', 'bin', 'vmservice', file);
     var libraryOut = path.join(sdkOut, 'vmservice_io', file);
     _writeSync(libraryOut, readInputFile(libraryIn));
   }
 
+  final platform = path.join(outDir, 'platform.dill');
+
+  await compile_platform.mainEntryPoint(<String>[
+    '--packages',
+    new Uri.file(packagesFile).toString(),
+    new Uri.directory(outDir).toString(),
+    platform,
+  ]);
+
   // TODO(kustermann): We suppress compiler hints/warnings/errors temporarily
   // because everyone building the `runtime` target will get these now.
   // We should remove the suppression again once the underlying issues have
   // been fixed (either in fasta or the dart files in the patched_sdk).
   final capturedLines = <String>[];
   try {
-    final platform = path.join(outDir, 'platform.dill');
-
     await runZoned(() async {
-      await compile_platform.mainEntryPoint(<String>[
-        '--packages',
-        new Uri.file(packagesFile).toString(),
-        new Uri.directory(outDir).toString(),
-        platform,
-      ]);
-
       // platform.dill was generated, now generate platform.dill.d depfile
       // that captures all dependencies that participated in the generation.
       // There are two types of dependencies:
       //   (1) all Dart sources that constitute this tool itself
       //   (2) Dart SDK and patch sources.
       // We already collected all inputs from the second category in the deps
       // set. To collect inputs from the first category we actually use Fasta:
       // we ask Fasta to outline patch_sdk.dart and generate a depfile which
       // would list all the sources.
       final depfile = "${outDir}.d";
@@ skipping 369 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;
 }