Start accepting incoming sockets earlier on Windows, to associate a at AcceptEx error to 'ServerSoc…

runtime/bin/socket.h

Index: runtime/bin/socket.h
diff --git a/runtime/bin/socket.h b/runtime/bin/socket.h
index 9471c5a1ca6575dce6e5a0870ab0b11a5e2e2941..1d09ba82a8b9d259f5576306957a5e3bc6daa0e3 100644
--- a/runtime/bin/socket.h
+++ b/runtime/bin/socket.h
@@ -303,6 +303,10 @@ class ServerSocket {
                                    intptr_t backlog,
                                    bool v6_only = false);
 
+  // Start accepting on a newly created listening socket. If it was unable to
+  // start accepting incoming sockets, the fd is invalidated.
+  static bool StartAccept(intptr_t fd);
+
  private:
   DISALLOW_ALLOCATION();
   DISALLOW_IMPLICIT_CONSTRUCTORS(ServerSocket);