Reduce size of Engine.

src/packages/lang_core.rs

@@ -267,7 +267,8 @@ fn collect_fn_metadata(
     #[cfg(not(feature = "no_module"))]
     ctx.engine()
         .global_sub_modules
-        .values()
+        .iter()
+        .flat_map(|m| m.values())
         .flat_map(|m| m.iter_script_fn())
         .filter(|(ns, a, n, p, f)| filter(*ns, *a, n, *p, f))
         .for_each(|(.., f)| {