ninja windows: Support x64 configuration platform

test/assembly/src/override.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': [
+    {
+      'target_name': 'program',
+      'type': 'executable',
+      'sources': [
+        'program.c',
+        'override_asm.asm',
+      ],
+      'rules': [
+      {
+        # Test that if there's a specific .asm rule, it overrides the
+        # built in one on Windows.
+        'rule_name': 'assembler',
+        'msvs_cygwin_shell': 0,
+        'extension': 'asm',
+        'inputs': [
+          'as.bat',
+        ],
+        'outputs': [
+          'output.obj',
+        ],
+        'action': ['as.bat', 'lib1.c', '<(_outputs)'],
+        'message': 'Building assembly file <(RULE_INPUT_PATH)',
+        'process_outputs_as_sources': 1,
+        },
+      ],
+    },
+  ],
+}