add foldr/build optimisation for take and replicate

add foldr/build optimisation for take and replicate
This allows take to be deforested, and improves performance of
replicate and replicateM/replicateM_.  We have a separate problem that
means expressions involving [n..m] aren't being completely optimised
because eftIntFB isn't being inlined but otherwise the results look
good.

Sadly this has invalidated a number of the nofib benchmarks which were
erroneously using take to duplicate work in a misguided attempt to
lengthen their runtimes (ToDo).