Macro impl_obs_drop 

macro_rules! impl_obs_drop {
    ($struct_name: ident, $operation:expr) => { ... };
    ($struct_name: ident, ($($var:ident),* $(,)*), $operation:expr) => { ... };
}

Implement a non-panicking native cleanup guard.

Cleanup is enqueued on the runtime’s dedicated cleanup queue, so destructors do not synchronously execute libobs calls or require a Tokio runtime.