Make sure GYP supports compiling managed code.

test/win/compiler-flags/compile-as-managed.gyp

+# Copyright (c) 2015 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': 'test-compile-as-managed',
+      'type': 'executable',
+      'msvs_settings': {
+        'VCCLCompilerTool': {
+          'CompileAsManaged': 'true',
+          'ExceptionHandling': '0' # /clr is incompatible with /EHs
+        }
+      },
+      'sources': ['compile-as-managed.cc'],
+    },
+    {
+      'target_name': 'test-compile-as-unmanaged',
+      'type': 'executable',
+      'msvs_settings': {
+        'VCCLCompilerTool': {
+          'CompileAsManaged': 'false',
+        }
+      },
+      'sources': ['compile-as-managed.cc'],
+    },
+  ]
+}