Fix warnings on VS2015 x86_64 build

gyp/zlib.gyp

 # Copyright 2014 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
+  'variables': {
+    'skia_warnings_as_errors': 0,
+  },
   'targets': [
   {
     # Only used by win, down below.
     'target_name' : 'zlib_x86_simd',
     'type': 'static_library',
     'cflags' : ['-msse4.2', '-mpclmul'],
     'sources' : [
       '../third_party/externals/zlib/crc_folding.c',
       '../third_party/externals/zlib/fill_window_sse.c',
     ],
@@ skipping 69 matching lines @@
           'dependencies': [
             'zlib_x86_simd',
           ],
           'defines': [
             '_CRT_NONSTDC_NO_DEPRECATE',
           ],
         }],
       ],
   }],
 }