Fix mac build

runtime/bin/socket_macos.cc

 // Copyright (c) 2013, 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.
 
 #if !defined(DART_IO_DISABLED)
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_MACOS)
 
 #include "bin/socket.h"
 #include "bin/socket_macos.h"
 
 #include <errno.h>        // NOLINT
 #include <ifaddrs.h>      // NOLINT
 #include <net/if.h>       // NOLINT
 #include <netinet/tcp.h>  // NOLINT
 #include <stdio.h>        // NOLINT
 #include <stdlib.h>       // NOLINT
 #include <string.h>       // NOLINT
 #include <sys/stat.h>     // NOLINT
 #include <unistd.h>       // NOLINT
 
 #include "bin/fdutils.h"
 #include "bin/file.h"
 #include "platform/signal_blocker.h"
 
 namespace dart {
 namespace bin {
 
-static void FDUtils::SaveErrorAndClose(intptr_t fd) {
-  int err = errno;
-  VOID_TEMP_FAILURE_RETRY(close(fd));
-  errno = err;
-}
-
-
 SocketAddress::SocketAddress(struct sockaddr* sa) {
   ASSERT(INET6_ADDRSTRLEN >= INET_ADDRSTRLEN);
   if (!Socket::FormatNumericAddress(*reinterpret_cast<RawAddr*>(sa), as_string_,
                                     INET6_ADDRSTRLEN)) {
     as_string_[0] = 0;
   }
   socklen_t salen = GetAddrLength(*reinterpret_cast<RawAddr*>(sa));
   memmove(reinterpret_cast<void*>(&addr_), sa, salen);
 }
 
@@ skipping 584 matching lines @@
                             int interfaceIndex) {
   return JoinOrLeaveMulticast(fd, addr, interface, interfaceIndex, false);
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_MACOS)
 
 #endif  // !defined(DART_IO_DISABLED)