Remove unused thread pool from standalone VM binary.

runtime/bin/eventhandler_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 "bin/eventhandler.h"
 
 #include <errno.h>
 #include <pthread.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/event.h>
 #include <sys/time.h>
 #include <unistd.h>
 
 #include "bin/dartutils.h"
 #include "bin/fdutils.h"
 #include "bin/hashmap.h"
+#include "platform/thread.h"
 #include "platform/utils.h"
 
 
 int64_t GetCurrentTimeMilliseconds() {
   struct timeval tv;
   if (gettimeofday(&tv, NULL) < 0) {
     UNREACHABLE();
     return 0;
   }
   return ((static_cast<int64_t>(tv.tv_sec) * 1000000) + tv.tv_usec) / 1000;
@@ skipping 374 matching lines @@
 void* EventHandlerImplementation::GetHashmapKeyFromFd(intptr_t fd) {
   // The hashmap does not support keys with value 0.
   return reinterpret_cast<void*>(fd + 1);
 }
 
 
 uint32_t EventHandlerImplementation::GetHashmapHashFromFd(intptr_t fd) {
   // The hashmap does not support keys with value 0.
   return dart::Utils::WordHash(fd + 1);
 }