+rnForAll doc exp [] [] ty = rnHsType doc ty
+ -- One reason for this case is that a type like Int#
+ -- starts of as (HsForAllTy Nothing [] Int), in case
+ -- there is some quantification. Now that we have quantified
+ -- and discovered there are no type variables, it's nicer to turn
+ -- it into plain Int. If it were Int# instead of Int, we'd actually
+ -- get an error, because the body of a genuine for-all is
+ -- of kind *.
+