then rnLPat pat `thenM` \ (pat', fvs1) ->
rnHsTypeFVs doc ty `thenM` \ (ty', fvs2) ->
returnM (SigPatIn pat' ty', fvs1 `plusFV` fvs2)
then rnLPat pat `thenM` \ (pat', fvs1) ->
rnHsTypeFVs doc ty `thenM` \ (ty', fvs2) ->
returnM (SigPatIn pat' ty', fvs1 `plusFV` fvs2)