util: make offsetof/parent-of-member actually constexpr

libraries/libstratosphere/source/cfg/cfg_override.cpp

@@ -84,6 +84,8 @@ namespace ams::cfg {
             .override_any_app = true,
         };
 
+        bool g_loaded_override_config = false;
+
         char g_hbl_sd_path[0x100] = "/atmosphere/hbl.nsp";
 
         /* Helpers. */