Provides some of the missing POSIX file syscalls

src/trusted/desc/nacl_desc_imc_shm.c

 /*
  * Copyright (c) 2012 The Native Client Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /*
  * NaCl Service Runtime.  Transferrable shared memory objects.
  */
 
@@ skipping 321 matching lines @@
 #else
   NACL_DESC_UNMAP_NOT_IMPLEMENTED
 #endif
   NaClDescReadNotImplemented,
   NaClDescWriteNotImplemented,
   NaClDescSeekNotImplemented,
   NaClDescPReadNotImplemented,
   NaClDescPWriteNotImplemented,
   NaClDescIoctlNotImplemented,
   NaClDescImcShmFstat,
+  NaClDescFchdirNotImplemented,
+  NaClDescFchmodNotImplemented,
+  NaClDescFsyncNotImplemented,
+  NaClDescFdatasyncNotImplemented,
+  NaClDescFtruncateNotImplemented,
   NaClDescGetdentsNotImplemented,
   NaClDescImcShmExternalizeSize,
   NaClDescImcShmExternalize,
   NaClDescLockNotImplemented,
   NaClDescTryLockNotImplemented,
   NaClDescUnlockNotImplemented,
   NaClDescWaitNotImplemented,
   NaClDescTimedWaitAbsNotImplemented,
   NaClDescSignalNotImplemented,
   NaClDescBroadcastNotImplemented,
@@ skipping 57 matching lines @@
 
   *out_desc = (struct NaClDesc *) ndisp;
   rv = 0;
 
 cleanup:
   if (rv < 0) {
     NaClDescSafeUnref((struct NaClDesc *) ndisp);
   }
   return rv;
 }