Fix debugging module(replace int with intptr_t) so it works on Windows x64.

runtime/bin/dbg_connection_macos.cc

 // 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.
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_MACOS)
 
 #include <errno.h>  // NOLINT
 #include <stdio.h>  // NOLINT
 #include <stdlib.h>  // NOLINT
@@ skipping 58 matching lines @@
   return remaining == 0;
 }
 
 
 void DebuggerConnectionImpl::HandleEvent(struct kevent* event) {
   int ident = event->ident;
   if (ident == DebuggerConnectionHandler::listener_fd_) {
     if (DebuggerConnectionHandler::IsConnected()) {
       FATAL("Cannot connect to more than one debugger.\n");
     }
-    int fd = ServerSocket::Accept(ident);
+    intptr_t fd = ServerSocket::Accept(ident);
     if (fd < 0) {
       FATAL("Accepting new debugger connection failed.\n");
     }
     FDUtils::SetBlocking(fd);
     DebuggerConnectionHandler::AcceptDbgConnection(fd);
 
     /* For now, don't poll the debugger connection.
     struct kevent ev_add;
     EV_SET(&ev_add, fd, EVFILT_READ, EV_ADD, 0, 0, NULL);
     int status =
@@ skipping 95 matching lines @@
 
 
 intptr_t DebuggerConnectionImpl::Receive(intptr_t socket, char* buf, int len) {
   return TEMP_FAILURE_RETRY(read(socket, buf, len));
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_MACOS)