Fix Path.rm_rf
Fix Path.rm_rf

It didn't delete the toplevel directory

dra27/jbuilder,janestreet/jbuilder,rdavison/jbuilder,janestreet/jbuilder,dra27/jbuilder,rdavison/jbuilder,janestreet/jbuilder,janestreet/jbuilder,janestreet/jbuilder,dra27/jbuilder,dra27/jbuilder,dra27/jbuilder,janestreet/jbuilder,dra27/jbuilder