Revert unrelated changes

Author: DZakh

jscomp/ml/matching.ml

@@ -2299,19 +2299,23 @@ let combine_constructor sw_names loc arg ex_pat cstr partial ctx def
  | None ->
  begin match extension_cases with
  | (_, act)::rem -> act, rem
- | _ -> failwith "Empty extension case list is not possible"
+ | _ -> assert false
  end
  | Some fail -> fail, extension_cases in
  match extension_cases with
  | [] -> default
  | _ ->
- List.fold_right
- (fun (path, act) rem ->
- let ext = transl_extension_path ex_pat.pat_env path in
- Lifthenelse(Lprim(extension_slot_eq , [arg; ext], loc),
- act, rem))
- extension_cases
- default 
+ let tag = Ident.create "tag" in
+ let tests =
+ List.fold_right
+ (fun (path, act) rem ->
+ let ext = transl_extension_path ex_pat.pat_env path in
+ Lifthenelse(Lprim(extension_slot_eq , [Lvar tag; ext], loc),
+ act, rem))
+ extension_cases
+ default
+ in
+ Llet(Alias, Pgenval,tag, arg, tests)
  in
  lambda1, jumps_union local_jumps total1
  end else begin

jscomp/ml/predef.ml

@@ -140,6 +140,18 @@ and ident_assert_failure = ident_create_predef_exn "Assert_failure"
 and ident_undefined_recursive_module =
  ident_create_predef_exn "Undefined_recursive_module"
 
+let all_predef_exns = [
+ ident_match_failure;
+ ident_invalid_argument;
+ ident_failure;
+ ident_js_error;
+ ident_not_found;
+ ident_end_of_file;
+ ident_division_by_zero;
+ ident_assert_failure;
+ ident_undefined_recursive_module;
+]
+
 let path_match_failure = Pident ident_match_failure
 and path_assert_failure = Pident ident_assert_failure
 and path_undefined_recursive_module = Pident ident_undefined_recursive_module

jscomp/ml/predef.mli

@@ -77,6 +77,13 @@ val build_initial_env:
 val builtin_values: (string * Ident.t) list
 val builtin_idents: (string * Ident.t) list
 
+(** All predefined exceptions, exposed as [Ident.t] for flambda (for
+ building value approximations).
+ The [Ident.t] for division by zero is also exported explicitly
+ so flambda can generate code to raise it. *)
+val ident_division_by_zero: Ident.t
+val all_predef_exns : Ident.t list
+
 type test =
  | For_sure_yes
  | For_sure_no