Fix memory leak in MacOS process handling.

runtime/bin/eventhandler_macos.cc

 // 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.
 
 #include <errno.h>
 #include <poll.h>
 #include <pthread.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/time.h>
@@ skipping 182 matching lines @@
 }
 
 #ifdef DEBUG_POLL
 static void PrintEventMask(struct pollfd* pollfd) {
   printf("%d ", pollfd->fd);
   if ((pollfd->revents & POLLIN) != 0) printf("POLLIN ");
   if ((pollfd->revents & POLLPRI) != 0) printf("POLLPRI ");
   if ((pollfd->revents & POLLOUT) != 0) printf("POLLOUT ");
   if ((pollfd->revents & POLLERR) != 0) printf("POLLERR ");
   if ((pollfd->revents & POLLHUP) != 0) printf("POLLHUP ");
-  if ((pollfd->revents & POLLRDHUP) != 0) printf("POLLRDHUP ");
   if ((pollfd->revents & POLLNVAL) != 0) printf("POLLNVAL ");
-  int all_events = POLLIN | POLLPRI | POLLOUT |
-                   POLLERR | POLLHUP | POLLRDHUP | POLLNVAL;
+  int all_events = POLLIN | POLLPRI | POLLOUT | POLLERR | POLLHUP | POLLNVAL;
   if ((pollfd->revents & ~all_events) != 0) {
     printf("(and %08x) ", pollfd->revents & ~all_events);
   }
   printf("(available %d) ", FDUtils::AvailableBytes(pollfd->fd));
 
   printf("\n");
 }
 #endif
 
 intptr_t EventHandlerImplementation::GetPollEvents(struct pollfd* pollfd) {
@@ skipping 152 matching lines @@
     FATAL("Create start event handler thread");
   }
 }
 
 
 void EventHandlerImplementation::SendData(intptr_t id,
                                           Dart_Port dart_port,
                                           intptr_t data) {
   WakeupHandler(id, dart_port, data);
 }