[NaCl SDK] Add arm gcc toolchain support to the SDK

native_client_sdk/src/libraries/nacl_mounts/kernel_handle.cc

 /* Copyright (c) 2012 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "nacl_mounts/kernel_handle.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <pthread.h>
+#include <unistd.h>
 
 #include "nacl_mounts/mount.h"
 #include "nacl_mounts/mount_node.h"
 
 // It is only legal to construct a handle while the kernel lock is held.
 KernelHandle::KernelHandle(Mount* mnt, MountNode* node, int mode)
     : mount_(mnt),
       node_(node),
       mode_(mode),
       offs_(0) {
@@ skipping 21 matching lines @@
   // end and the new end.
   if (offs_ > node_->GetSize()) {
     if (node_->Truncate(offs_) < 0) {
       errno = EINVAL;
       return -1;
     }
   }
 
   return offs_;
 }