Fixes ABI bug in MIPS.

samples/sample_extension/sample_extension_no_autoscope_dllmain_win.cc

Index: samples/sample_extension/sample_extension_no_autoscope_dllmain_win.cc
===================================================================
--- samples/sample_extension/sample_extension_no_autoscope_dllmain_win.cc	(revision 0)
+++ samples/sample_extension/sample_extension_no_autoscope_dllmain_win.cc	(revision 0)
@@ -0,0 +1,16 @@
+// 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.
+
+#if defined(_WIN32)
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+BOOL APIENTRY DllMain(HMODULE module,
+                      DWORD  reason,
+                      LPVOID reserved) {
+  return true;
+}
+
+#endif  // defined(_WIN32)