[NaCk SDK] nacl_io: Don't assume ~S_IFMT are the mode bits.

native_client_sdk/src/libraries/nacl_io/kernel_object.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_io/kernel_object.h"
 
 #include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <pthread.h>
@@ skipping 144 matching lines @@
   return 0;
 }
 
 mode_t KernelObject::GetUmask() {
   return umask_;
 }
 
 mode_t KernelObject::SetUmask(mode_t newmask) {
   AUTO_LOCK(umask_lock_);
   mode_t oldmask = umask_;
-  umask_ = newmask & 0777;
+  umask_ = newmask & S_MODEBITS;
   return oldmask;
 }
 
 Error KernelObject::GetFDFlags(int fd, int* out_flags) {
   AUTO_LOCK(handle_lock_);
   if (fd < 0 || fd >= static_cast<int>(handle_map_.size()))
     return EBADF;
 
   *out_flags = handle_map_[fd].flags;
   return 0;
@@ skipping 89 matching lines @@
   AUTO_LOCK(handle_lock_);
 
   handle_map_[fd].handle.reset(NULL);
   free_fds_.push_back(fd);
 
   // Force lower numbered FD to be available first.
   std::push_heap(free_fds_.begin(), free_fds_.end(), std::greater<int>());
 }
 
 }  // namespace nacl_io