SimplexStream does not close other half on drop

[SteveLauC]

Upstream tokio issue: tokio-rs/tokio#6914

Root cause

Tokio duplex (or monoio-duplex) uses Arc or Rc when being split, the read half and write half are the same SimplexStream structure, dropping one side does nothing to the SimpleStream structure, and reading/writing through the Rc/Arc wrapper won't check its reference count.

Code snippet

#[monoio::main]
async fn main() {
    use monoio::io::AsyncWriteRentExt;

    let (rx, mut tx) = monoio_duplex::simplex::simplex(64);
    drop(rx);
    let buf = [0; 1024];
    println!("write starting");
    let (write_result, _buf)  = tx.write_all(buf.to_vec()).await;
    write_result.unwrap();
    println!("write finished")
}