Building a fresh checkout on RHEL 5 has been broken since commit
29db7a00, due to a gnulib regression in the bootstrap script
(incremental builds from a checkout earlier than that point were
okay, though).

* .gnulib: Update to latest, for bootstrap fixes.
* bootstrap: Resync from gnulib.
* gnulib/local/top/maint.mk.diff: Drop patch that was added
upstream in the meantime.