Provides some of the missing POSIX file syscalls

src/trusted/desc/nacl_desc_rng.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.
  */
 
 /*
  * A NaClDesc subclass that exposes the platform secure RNG
  * implementation.
  */
@@ skipping 127 matching lines @@
   },
   NaClDescMapNotImplemented,
   NACL_DESC_UNMAP_NOT_IMPLEMENTED
   NaClDescRngRead,
   NaClDescRngWrite,
   NaClDescSeekNotImplemented,
   NaClDescPReadNotImplemented,
   NaClDescPWriteNotImplemented,
   NaClDescIoctlNotImplemented,
   NaClDescRngFstat,
+  NaClDescFchdirNotImplemented,
+  NaClDescFchmodNotImplemented,
+  NaClDescFsyncNotImplemented,
+  NaClDescFdatasyncNotImplemented,
+  NaClDescFtruncateNotImplemented,
   NaClDescGetdentsNotImplemented,
   NaClDescRngExternalizeSize,
   NaClDescRngExternalize,
   NaClDescLockNotImplemented,
   NaClDescTryLockNotImplemented,
   NaClDescUnlockNotImplemented,
   NaClDescWaitNotImplemented,
   NaClDescTimedWaitAbsNotImplemented,
   NaClDescSignalNotImplemented,
   NaClDescBroadcastNotImplemented,
@@ skipping 36 matching lines @@
     goto cleanup;
   }
   *out_desc = (struct NaClDesc *) rng;
   rv = 0;  /* yay! */
  cleanup:
   if (rv < 0) {
     NaClDescSafeUnref((struct NaClDesc *) rng);
   }
   return rv;
 }