chore: use ready macro from futures-core (#1300)

tokio-io/src/async_read.rs

@@ -1,6 +1,7 @@
 //use crate::split::{ReadHalf, WriteHalf};
 //use crate::{framed, split, AsyncWrite};
 use bytes::BufMut;
+use futures_core::ready;
 use std::io;
 use std::ops::DerefMut;
 use std::pin::Pin;

tokio-io/src/async_write.rs

@@ -1,5 +1,6 @@
 //use crate::AsyncRead;
 use bytes::Buf;
+use futures_core::ready;
 use std::io;
 use std::ops::DerefMut;
 use std::pin::Pin;

tokio-io/src/lib.rs

@@ -12,15 +12,6 @@
 //! [found online]: https://tokio.rs/docs/
 //! [low level details]: https://tokio.rs/docs/going-deeper-tokio/core-low-level/
 
-macro_rules! ready {
-    ($e:expr) => {
-        match $e {
-            ::std::task::Poll::Ready(t) => t,
-            ::std::task::Poll::Pending => return ::std::task::Poll::Pending,
-        }
-    };
-}
-
 mod async_read;
 mod async_write;