Apply a patch (patch-b*) to xen-3.1.0 to fix the ELF loader so that the
symbol table is properly loaded for the NetBSD dom0 kernel. This is from
the Xen repository, based on a patch inistally submitted by Christoph Egger
to Xen (thanks !). Should fix PR port-xen/36671.
While there also provide a debug Xen kernel, built with debug=1.
Bump PKGREVISION.