Make lines stricter to fix a space leak

[Bertram Felgenhauer]

Simon Marlow wrote:
[snip]
> The other problem in this area is that the simplifier tends to
> transform code such that selector thunks aren't recognisable any
> more, so the GC optimisation doesn't apply.  I think we have a
> ticket for this one (but as I'm on a plane right now I can't find
> it).

This is the ticket: http://hackage.haskell.org/trac/ghc/ticket/2607

HTH,

Bertram