Add some gnulib.modules

* gnulib.modules: Add errno, limits-h, safe-read, sys_stat.
Not sure about the relationship between gnulib.modules
and paxutils/gnulib.modules, but anyway tar itself uses
these so we should depend on them.  (Perhaps it would be
better if there was just one Gnulib module list for tar;
that would be less confusing.)

gnulib.modules

@@ -32,6 +32,7 @@ closeout
 configmake
 dirname
 dup2
+errno
 error
 exclude
 extern-inline
@@ -65,6 +66,7 @@ inttostr
 inttypes
 largefile
 lchown
+limits-h
 linkat
 localcharset
 manywarnings
@@ -86,6 +88,7 @@ renameat
 root-uid
 rpmatch
 full-read
+safe-read
 savedir
 selinux-at
 setenv
@@ -104,6 +107,7 @@ strtol
 strtoul
 strtoumax
 symlinkat
+sys_stat
 timespec
 timespec-sub
 unlinkat