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