Provides some of the missing POSIX file syscalls

src/trusted/desc/nacl_desc_quota.c

Index: src/trusted/desc/nacl_desc_quota.c
diff --git a/src/trusted/desc/nacl_desc_quota.c b/src/trusted/desc/nacl_desc_quota.c
index c3ec15d2da404d1a034c67eb47a403a12efe5eba..3fe663edb7616d5c53bf94181fd9f35073939644 100644
--- a/src/trusted/desc/nacl_desc_quota.c
+++ b/src/trusted/desc/nacl_desc_quota.c
@@ -273,6 +273,38 @@ int NaClDescQuotaFstat(struct NaClDesc      *vself,
   return (*NACL_VTBL(NaClDesc, self->desc)->Fstat)(self->desc, statbuf);
 }
 
+int NaClDescQuotaFchdir(struct NaClDesc *vself) {
+  struct NaClDescQuota  *self = (struct NaClDescQuota *) vself;
+
+  return (*NACL_VTBL(NaClDesc, self->desc)->Fchdir)(self->desc);
+}
+
+int NaClDescQuotaFchmod(struct NaClDesc *vself,
+                        int             mode) {
+  struct NaClDescQuota  *self = (struct NaClDescQuota *) vself;
+
+  return (*NACL_VTBL(NaClDesc, self->desc)->Fchmod)(self->desc, mode);
+}
+
+int NaClDescQuotaFsync(struct NaClDesc *vself) {
+  struct NaClDescQuota  *self = (struct NaClDescQuota *) vself;
+
+  return (*NACL_VTBL(NaClDesc, self->desc)->Fsync)(self->desc);
+}
+
+int NaClDescQuotaFdatasync(struct NaClDesc *vself) {
+  struct NaClDescQuota  *self = (struct NaClDescQuota *) vself;
+
+  return (*NACL_VTBL(NaClDesc, self->desc)->Fdatasync)(self->desc);
+}
+
+int NaClDescQuotaFtruncate(struct NaClDesc  *vself,
+                           nacl_abi_off_t   length) {
+  struct NaClDescQuota  *self = (struct NaClDescQuota *) vself;
+
+  return (*NACL_VTBL(NaClDesc, self->desc)->Ftruncate)(self->desc, length);
+}
+
 ssize_t NaClDescQuotaGetdents(struct NaClDesc *vself,
                               void            *dirp,
                               size_t          count) {
@@ -527,6 +559,11 @@ static struct NaClDescVtbl const kNaClDescQuotaVtbl = {
   NaClDescQuotaPWrite,
   NaClDescQuotaIoctl,
   NaClDescQuotaFstat,
+  NaClDescQuotaFchdir,
+  NaClDescQuotaFchmod,
+  NaClDescQuotaFsync,
+  NaClDescQuotaFdatasync,
+  NaClDescQuotaFtruncate,
   NaClDescQuotaGetdents,
   NaClDescQuotaExternalizeSize,
   NaClDescQuotaExternalize,