Explicitly handle listen sockets and connection sockets differently in Linux and Mac OS eventhandler

runtime/bin/eventhandler_macos.h

 // Copyright (c) 2011, 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.
 
 #ifndef BIN_EVENTHANDLER_MACOS_H_
 #define BIN_EVENTHANDLER_MACOS_H_
 
 
 typedef struct {
   intptr_t id;
@@ skipping 24 matching lines @@
   void UnregisterFdWakeup(intptr_t id);
   void CloseFd(intptr_t id);
   void UnregisterFd(intptr_t id);
   void HandleEvents(struct pollfd* pollfds, int pollfds_size, int result_size);
   void HandleTimeout();
   static void* Poll(void* args);
   void WakeupHandler(intptr_t id, Dart_Port dart_port, int64_t data);
   void HandleInterruptFd();
   void SetPort(intptr_t fd, Dart_Port dart_port, intptr_t mask);
   Dart_Port PortFor(intptr_t fd);
+  bool IsListeningSocket(intptr_t fd);
   intptr_t GetPollEvents(struct pollfd* pollfd);
   void SetPollEvents(struct pollfd* pollfds, intptr_t mask);
 
   PortData* port_map_;
   intptr_t port_map_entries_;
   intptr_t port_map_size_;
   int64_t timeout_;  // Time for next timeout.
   Dart_Port timeout_port_;
   int interrupt_fds_[2];
 };
 
 
 #endif  // BIN_EVENTHANDLER_MACOS_H_