[jhc] building transformers library, irrefutable patterns

[Korcan Hussein]

Hello I can build all of transformers (http://hackage.haskell.org/package/transformers) but only when excluding the files:

Control.Monad.Trans.RWS.Lazy,
Control.Monad.Trans.State.Lazy,
Control.Monad.Trans.Writer.Lazy

Which use irrefutable patterns, I could probably make this work without them but I just thought it was worth mentioning.