ninja windows: Fix special variables not getting emitted when expanded from VS macros

test/rules/src/special-variables.gyp

+# 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': [
+    {
+      'rules': [
+        {
+          'rule_name': 'assembler (gnu-compatible)',
+          'msvs_cygwin_shell': 0,
+          'msvs_quote_cmd': 0,
+          'extension': 'S',
+          'inputs': [
+            'as.bat',
+            '$(InputPath)'
+          ],
+          'outputs': [
+            '$(IntDir)/$(InputName).obj',
+          ],
+          'action': [
+            'as.bat',
+            '$(InputPath)',
+            '$(IntDir)/$(InputName).obj',
+          ],
+          'message': 'Building assembly language file $(InputPath)',
+          'process_outputs_as_sources': 1,
+        },
+      ],
+      'target_name': 'test',
+      'type': 'static_library',
+      'sources': [ 'an_asm.S' ],
+    },
+  ],
+}