-- The "{=(a,b)}" is an unfolding we can't reconstruct otherwise.
simplLamBndr env bndr
| isId bndr && hasSomeUnfolding old_unf = seqId id2 `seq` return (env2, id2) -- Special case
-- The "{=(a,b)}" is an unfolding we can't reconstruct otherwise.
simplLamBndr env bndr
| isId bndr && hasSomeUnfolding old_unf = seqId id2 `seq` return (env2, id2) -- Special case