Force not-Unicode version of libdart_builtin.

runtime/bin/bin.gypi

 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 {
   'variables': {
     'io_cc_file': '<(SHARED_INTERMEDIATE_DIR)/io_gen.cc',
     'json_cc_file': '<(SHARED_INTERMEDIATE_DIR)/json_gen.cc',
     'uri_cc_file': '<(SHARED_INTERMEDIATE_DIR)/uri_gen.cc',
     'utf8_cc_file': '<(SHARED_INTERMEDIATE_DIR)/utf8_gen.cc',
@@ skipping 198 matching lines @@
         'builtin.h',
       ],
       'includes': [
         'builtin_impl_sources.gypi',
         '../platform/platform_sources.gypi',
       ],
       'sources/': [
         ['exclude', '_test\\.(cc|h)$'],
       ],
       'conditions': [
-        ['OS=="win"', {'sources/' : [
-          ['exclude', 'fdutils.h'],
-        ]}],
+        ['OS=="win"', {
+          'sources/' : [
+            ['exclude', 'fdutils.h'],
+          ],
+          # TODO(antonm): fix the implementation.
+          # Current implementation accepts char* strings
+          # and therefore fails to compile once _UNICODE is
+          # enabled.  That should be addressed using -A
+          # versions of functions and adding necessary conversions.
+          'msvs_configuration_attributes': {
+            'CharacterSet': '0',
+          },
+        }],
         ['OS=="linux"', {
           'link_settings': {
             'libraries': [
               '-ldl',
             ],
           },
         }],
       ],
     },
     {
@@ skipping 192 matching lines @@
           ],
           'defines': [
             'DART_SHARED_LIB',
           ],
         },
       ],
     }],
   ],
 }