Make pub's binstubs resilient to changes in snapshot format.

sdk/lib/_internal/pub/test/cache/repair/recompiles_snapshots_test.dart

 // Copyright (c) 2014, 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 pub_tests;
+
+import 'package:scheduled_test/scheduled_test.dart';
+
 import '../../descriptor.dart' as d;
 import '../../test_pub.dart';
 
 main() {
   initConfig();
-  integration('runs a script in an activated package', () {
+  integration('recompiles activated executable snapshots', () {
     servePackages((builder) {
       builder.serve("foo", "1.0.0", contents: [
         d.dir("bin", [
           d.file("script.dart", "main(args) => print('ok');")
         ])
       ]);
     });
 
     schedulePub(args: ["global", "activate", "foo"]);
 
+    d.dir(cachePath, [
+      d.dir('global_packages/foo/bin', [
+        d.file('script.dart.snapshot', 'junk')
+      ])
+    ]).create();
+
+    schedulePub(args: ["cache", "repair"],
+        output: '''
+          Downloading foo 1.0.0...
+          Reinstalled 1 package.
+          Reactivating foo 1.0.0...
+          Precompiling executables...
+          Loading source assets...
+          Precompiled foo:script.
+          Reactivated 1 package.''');
+
     var pub = pubRun(global: true, args: ["foo:script"]);
     pub.stdout.expect("ok");
     pub.shouldExit();
   });
 }