simplify check of private assignment

Author: tsnobip

compiler/ml/typecore.ml

@@ -313,15 +313,6 @@ let extract_concrete_record env ty =
   match extract_concrete_typedecl env ty with
   | p0, p, {type_kind = Type_record (fields, repr)} -> (p0, p, fields, repr)
   | _ -> raise Not_found
-
-let private_record_allows_mutation env label =
-  match extract_concrete_typedecl env label.lbl_res with
-  | _, _, {type_kind = Type_record _; type_private = Private; type_attributes}
-    ->
-    Builtin_attributes.has_allow_mutation type_attributes
-  | _ -> false
-  | exception Not_found -> false
-
 let extract_concrete_variant env ty =
   match extract_concrete_typedecl env ty with
   | p0, p, {type_kind = Type_variant cstrs} -> (p0, p, cstrs)
@@ -3472,10 +3463,12 @@ and type_label_exp ~call_context create env loc ty_expected
     (* Generalize information merged from ty_expected *)
     generalize_structure ty_arg);
   let allow_private_assignment =
-    match call_context with
-    | `SetRecordField when not create ->
-      private_record_allows_mutation env label
+    match extract_concrete_typedecl env label.lbl_res with
+    | _, _, {type_kind = Type_record _; type_private = Private; type_attributes}
+      when not create ->
+      Builtin_attributes.has_allow_mutation type_attributes
     | _ -> false
+    | exception Not_found -> false
   in
   if label.lbl_private = Private && not allow_private_assignment then
     if create then raise (Error (loc, env, Private_type ty_expected))