error[E0277]: `Rc<Cell<i32>>` cannot be sent between threads safely
  --> $DIR/non_send.rs:11:9
   |
11 |       lua.create_function(move |_, ()| {
   |  _________^^^^^^^^^^^^^^^_-
   | |         |
   | |         `Rc<Cell<i32>>` cannot be sent between threads safely
12 | |         Ok(data.get())
13 | |     })?
   | |_____- within this `[closure@$DIR/tests/compile/non_send.rs:11:25: 13:6]`
   |
   = help: within `[closure@$DIR/tests/compile/non_send.rs:11:25: 13:6]`, the trait `Send` is not implemented for `Rc<Cell<i32>>`
   = note: required because it appears within the type `[closure@$DIR/tests/compile/non_send.rs:11:25: 13:6]`
   = note: required because of the requirements on the impl of `mlua::types::MaybeSend` for `[closure@$DIR/tests/compile/non_send.rs:11:25: 13:6]`