Currently we duplicate top-level binder ids for no reason:

    $fEqHsExpr_$c/=
    $fEqHsExpr_$c/=
      = \ @ id_a27U $dEq_a27V eta_B2 eta1_B1 ->
          case $fEqHsExpr_$c== $dEq_a27V eta_B2 eta1_B1 of {
            False -> True;
            True -> False
          }

with this patch we drop the first line when type signatures are not
printed (-dsuppress-type-signatures, which is implied by -dsuppress-all)

Reviewers: simonpj, bgamari

Reviewed By: simonpj

Subscribers: rwbarton, carter

Differential Revision: https://phabricator.haskell.org/D5472