Add native extensions to the Dart shell, on the linux platform.

tests/standalone/src/test_extension.dart

Index: tests/standalone/src/test_extension.dart
diff --git a/tests/standalone/src/test_extension.dart b/tests/standalone/src/test_extension.dart
new file mode 100644
index 0000000000000000000000000000000000000000..c166e450804faa56e10f24c1398d2d12fde40369
--- /dev/null
+++ b/tests/standalone/src/test_extension.dart
@@ -0,0 +1,17 @@
+// 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.
+
+#library("test_extension");
+
+#import("dartext:test_extension");
+
+class Cat {
+  Cat(this.x);
+
+  num x;
+
+  String toString() => 'cat $x';
+
+  static int ifNull(a, b) native 'Cat_IfNull';

[Mads Ager (google), 2012/02/23 09:26:56]

Could you add a comment to this? I don't understand why this is called ifNull?

+}