Enabling /ZW (CompileAsWinRT) option for msvs

test/win/compiler-flags/compile-as-winrt.cc

Index: test/win/compiler-flags/compile-as-winrt.cc
diff --git a/test/win/compiler-flags/compile-as-winrt.cc b/test/win/compiler-flags/compile-as-winrt.cc
new file mode 100644
index 0000000000000000000000000000000000000000..d10f6a5e4a6e3c8958a1d9b09a9b5a9bbd9620f6
--- /dev/null
+++ b/test/win/compiler-flags/compile-as-winrt.cc
@@ -0,0 +1,12 @@
+// Copyright (c) 2016 Microsoft. All rights reserved.

[scottmg, 2016/04/04 22:05:17]

I think copyright is supposed to be assigned to "Google Inc." in gyp code.

[munyirik, 2016/04/11 20:07:10]

Acknowledged.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+using namespace Platform;
+
+int main() {
+  wchar_t msg[] = L"Test";
+  String^ str1 = ref new String(msg);
+  auto str2 = String::Concat(str1, " Concat");
+  return 0;
+}