loop`count attribute

11.9: adda/cstr/loop`count attribute:
. this is a language add-on
that can simplify control var's:
instead of having to
declare and init' a loop var in the head,
and then increment it in the body,
every loop understands "(loop`count),
or "(LOOPLABEL`count) .
. labels are good for nested loops:
when you're in the inner one,
and you want the count of the outer one,
you'll then need a label for the outer one .