Enable/disable various dirs in src-release.sh

Enable/disable various dirs in src-release.sh

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.