Promote nbody-blc-ref from a future

r23772 added references to Chapel, so we can remove this future.
nobdy-blc-ref will run as a performance test as well now.


git-svn-id: http://svn.code.sf.net/p/chapel/code/trunk@23773 3a8e244f-b0f2-452b-bcba-4c88e055c3ca