This is an experimental change suggested by Roman.  Consider
	
	{-# INLINE f #-}
	f x y = ...

	....(g (f a b))...

where g has RULES.  Then we'd like to inline f, even though the context of
the call is otherwise 100% boring -- g is lazy and we know nothing about
x and y. 

This patch just records in the continuation that f has rules.  And does so
somewhat recursively...e.g.

	...(g (h (f a b)))...

where g has rules.