Get generate_dump compiling on Windows

compat/win/sys/types.h

 // Copyright 2014 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.
 
 #ifndef CRASHPAD_COMPAT_WIN_SYS_TYPES_H_
 #define CRASHPAD_COMPAT_WIN_SYS_TYPES_H_
 
 // This is intended to be roughly equivalent to #include_next.
 #include <../include/sys/types.h>
 
 #include <stdint.h>
 
 #ifdef _WIN64
 typedef int64_t ssize_t;
-typedef uint64_t pid_t;
 #else
 typedef __w64 int ssize_t;
-typedef __w64 unsigned int pid_t;
 #endif
 
+typedef unsigned int pid_t;
 
 #endif  // CRASHPAD_COMPAT_WIN_SYS_TYPES_H_