fix desugaring of irrefutable lambda bindings
fix desugaring of irrefutable lambda bindings

Ignore-this: 5c70934cbe42169850481562cd5b20f3

darcs-hash:20100810053944-1a7c6-430e33d876f707f2b21e4632adbe07e3332ec486

kirbyfan64/jhc,kirbyfan64/jhc,kirbyfan64/jhc,kirbyfan64/jhc