-Note [Enough args]
-~~~~~~~~~~~~~~~~~~
-At one stage we considered only inlining a function that has enough
-arguments to saturate its arity. But we can lose from this. For
-example (f . g) might not be a saturated application of (.), but
-nevertheless f and g might usefully optimise with each other if we
-inlined (.) and f and g.
-
-Current story (Jan08): inline even if not saturated.
-