these tests seem to work fine on Miri now

Author: RalfJung

tokio/tests/rt_basic.rs

@@ -1,6 +1,5 @@
 #![warn(rust_2018_idioms)]
 #![cfg(feature = "full")]
-#![cfg(not(miri))] // Possible bug on Miri.
 
 use tokio::runtime::Runtime;
 use tokio::sync::oneshot;