gnulib: update

* gnulib: here.

lib/.gitignore

@@ -272,3 +272,5 @@
 /sig-handler.c
 /unistd.c
 /wctype-h.c
+/lstat.c
+/unlink.c

m4/.gitignore

@@ -180,3 +180,6 @@
 /obstack-printf.m4
 /extern-inline.m4
 /non-recursive-gnulib-prefix-hack.m4
+/absolute-header.m4
+/lstat.m4
+/unlink.m4