message: Handle EINTR in the apple version of ExternalCommitHelper
  We just want to re-call kevent when it happens. The epoll version already did
  this.
diff: @@ -196,7 +196,7 @@ ExternalCommitHelper::~ExternalCommitHelper()
  void ExternalCommitHelper::listen()
  {
  - pthread_setname_np("RLMRealm notification listener");
  + pthread_setname_np("Realm notification listener");
  // Set up the kqueue
  // EVFILT_READ indicates that we care about data being available to read
  @@ -214,11 +214,11 @@ void ExternalCommitHelper::listen()
  // Wait for data to become on either fd
  // Return code is number of bytes available or -1 on error
  ret = kevent(m_kq, nullptr, 0, &event, 1, nullptr);
  - assert(ret >= 0);
  - if (ret == 0) {
  + if (ret == 0 || (ret < 0 && errno == EINTR)) {
  // Spurious wakeup; just wait again
  continue;
  }
  + assert(ret > 0);
  // Check which file descriptor had activity: if it's the shutdown
  // pipe, then someone called -stop; otherwise it's the named pipe
  