Remove obsolete "bs.open" feature

Author: cknitt

jscomp/frontend/ast_attributes.ml

@@ -93,13 +93,6 @@ let process_attributes_rev (attrs : t) : attr_kind * t =
         Bs_syntaxerr.err loc Conflict_bs_bs_this_bs_meth
       | _, _ -> (st, attr :: acc))
 
-let process_pexp_fun_attributes_rev (attrs : t) =
-  Ext_list.fold_left attrs (false, [])
-    (fun (st, acc) (({txt; loc = _}, _) as attr) ->
-      match txt with
-      | "bs.open" -> (true, acc)
-      | _ -> (st, attr :: acc))
-
 let process_bs (attrs : t) =
   Ext_list.fold_left attrs (false, [])
     (fun (st, acc) (({txt; loc = _}, _) as attr) ->

jscomp/frontend/ast_attributes.mli

@@ -37,8 +37,6 @@ type attr_kind =
 
 val process_attributes_rev : t -> attr_kind * t
 
-val process_pexp_fun_attributes_rev : t -> bool * t
-
 val process_bs : t -> bool * t
 
 val has_inline_payload : t -> attr option

jscomp/frontend/ast_bs_open.ml

@@ -110,16 +110,9 @@ let expr_mapper ~async_context ~in_function_def (self : mapper)
   | Pexp_constant (Pconst_integer (s, Some 'l')) ->
     {e with pexp_desc = Pexp_constant (Pconst_integer (s, None))}
   (* End rewriting *)
-  | Pexp_function cases -> (
-    (* {[ function [@bs.exn]
-         | Not_found -> 0
-         | Invalid_argument -> 1
-       ]}*)
+  | Pexp_function _ ->
     async_context := false;
-    match Ast_attributes.process_pexp_fun_attributes_rev e.pexp_attributes with
-    | false, _ -> default_expr_mapper self e
-    | true, pexp_attributes ->
-      Ast_bs_open.convertBsErrorFunction e.pexp_loc self pexp_attributes cases)
+    default_expr_mapper self e
   | _
     when Ast_uncurried.exprIsUncurriedFun e
          &&