gold needs to be enabled for a binutils release, but it's rather odd
to do so for gas, gdb or sim. This patch passes various --enable and
--disable options depending on the directories being released.
* src-release.sh (do_proto_toplev): Revert last patch. Enable or
disable binutils, gas, gdb, gold, gprof, ld, libdecnumber, readline,
and sim depending on $tool and $support_files. Echo configure line.