- Fix Isolate.spawn when running from snapshot.

runtime/bin/platform_patch.dart

 // Copyright (c) 2012, 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.
 
 patch class _Platform {
   /* patch */ static int _numberOfProcessors()
       native "Platform_NumberOfProcessors";
   /* patch */ static String _pathSeparator()
       native "Platform_PathSeparator";
   /* patch */ static String _operatingSystem()
       native "Platform_OperatingSystem";
   /* patch */ static _localHostname()
       native "Platform_LocalHostname";
   /* patch */ static _executable()
       native "Platform_ExecutableName";
   /* patch */ static _resolvedExecutable()
       native "Platform_ResolvedExecutableName";
   /* patch */ static _environment()
       native "Platform_Environment";
   /* patch */ static List<String> _executableArguments()
       native "Platform_ExecutableArguments";
   /* patch */ static String _version()
       native "Platform_GetVersion";
 
   /* patch */ static String _packageRoot()
       => VMLibraryHooks.packageRootString;
   /* patch */ static String _packageConfig()
       => VMLibraryHooks.packageConfigString;
+
+  // This script singleton is written to by the embedder if applicable.
+  /* patch */ static void set _nativeScript(String path) {
+    if (path.startsWith('http:') ||
+        path.startsWith('https:') ||
+        path.startsWith('package:') ||
+        path.startsWith('dart:') ||
+        path.startsWith('data:') ||
+        path.startsWith('file:')) {
+      script = Uri.parse(path);
+    } else {
+      script = Uri.base.resolveUri(new Uri.file(path));
+    }
+    VMLibraryHooks.platformScript = script;
+  }
 }