Makefile: add a 'natruntop' target, similar to 'runtop'
Makefile: add a 'natruntop' target, similar to 'runtop'

eliberis/ocaml,eliberis/ocaml,gerdstolpmann/ocaml,yunxing/ocaml,msprotz/ocaml,msprotz/ocaml,eliberis/ocaml,eliberis/ocaml,gerdstolpmann/ocaml,msprotz/ocaml,yunxing/ocaml,msprotz/ocaml,eliberis/ocaml,msprotz/ocaml,gerdstolpmann/ocaml,yunxing/ocaml,yunxing/ocaml,gerdstolpmann/ocaml,yunxing/ocaml,gerdstolpmann/ocaml