msvs: Prefer x64 toolset if we are running on 64-bit

pylib/gyp/generator/msvs.py

 # 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.
 
 import copy
 import ntpath
 import os
 import posixpath
 import re
 import subprocess
@@ skipping 2606 matching lines @@
   namespace = os.path.splitext(gyp_file_name)[0]
   properties = [
       ['PropertyGroup', {'Label': 'Globals'},
         ['ProjectGuid', guid],
         ['Keyword', 'Win32Proj'],
         ['RootNamespace', namespace],
         ['IgnoreWarnCompileDuplicatedFilename', 'true'],
       ]
     ]
 
+  if os.environ.get('PROCESSOR_ARCHITECTURE') == 'AMD64' or \
+     os.environ.get('PROCESSOR_ARCHITEW6432') == 'AMD64':
+    properties[0].append(['PreferredToolArchitecture', 'x64'])
+
   if spec.get('msvs_enable_winrt'):
     properties[0].append(['DefaultLanguage', 'en-US'])
     properties[0].append(['AppContainerApplication', 'true'])
     properties[0].append(['ApplicationTypeRevision', '8.1'])
 
     if spec.get('msvs_enable_winphone'):
       properties[0].append(['ApplicationType', 'Windows Phone'])
     else:
       properties[0].append(['ApplicationType', 'Windows Store'])
 
@@ skipping 779 matching lines @@
   action_spec.extend(
       # TODO(jeanluc) 'Document' for all or just if as_sources?
       [['FileType', 'Document'],
        ['Command', command],
        ['Message', description],
        ['Outputs', outputs]
       ])
   if additional_inputs:
     action_spec.append(['AdditionalInputs', additional_inputs])
   actions_spec.append(action_spec)