Add "standalone_static_library" flag

test/standalone-static-library/invalid.gyp

Index: test/standalone-static-library/invalid.gyp
===================================================================
--- test/standalone-static-library/invalid.gyp	(revision 0)
+++ test/standalone-static-library/invalid.gyp	(revision 0)
@@ -0,0 +1,16 @@
+# Copyright (c) 2012 Google Inc. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+{
+  'targets': [
+    {
+      'target_name': 'bad',
+      'type': 'executable',
+      'standalone_static_library': 1,
+      'sources': [
+        'prog.c',
+      ],
+    },
+  ],
+}