win: Compile getopt as C++ and wrap in crashpad namespace

third_party/getopt/getopt.gyp

 # Copyright 2015 The Crashpad Authors. All rights reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #     http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
 {
   'includes': [
     '../../build/crashpad.gypi',
   ],
   'conditions': [
     ['OS=="win"', {
       'targets': [
         {
           'target_name': 'getopt',
           'type': 'static_library',
           'sources': [
-            'getopt.c',
+            'getopt.cc',
             'getopt.h',
           ],
         },
       ],
     }, {
       'targets': []
     }]
   ],
 }