lua: loadstring wraps transpiled AST in (let () …) to contain local definitions

lib/lua/runtime.sx

@@ -1484,7 +1484,9 @@
 (define
   lua-loadstring
   (fn (src)
-    (fn (&rest args) (lua-eval-ast src))))
+    (let ((compiled (lua-transpile src)))
+      (fn (&rest args)
+        (eval-expr (list (make-symbol "let") (list) compiled))))))
 
 (define loadstring lua-loadstring)
 (define load lua-loadstring)