rt: simplify rt-* features (#2949)

tokio:

    merge rt-core and rt-util as rt
    rename rt-threaded to rt-multi-thread

tokio-util:

    rename rt-core to rt

Closes #2942

1 files changed, 3 insertions, 3 deletions

diff --git a/tokio/src/blocking.rs b/tokio/src/blocking.rs
index d6ef5915..f88b1db1 100644
--- a/tokio/src/blocking.rs
+++ b/tokio/src/blocking.rs
@@ -1,9 +1,9 @@
-cfg_rt_core! {
+cfg_rt! {
     pub(crate) use crate::runtime::spawn_blocking;
     pub(crate) use crate::task::JoinHandle;
 }
 
-cfg_not_rt_core! {
+cfg_not_rt! {
     use std::fmt;
     use std::future::Future;
     use std::pin::Pin;
@@ -15,7 +15,7 @@ cfg_not_rt_core! {
         R: Send + 'static,
     {
         assert_send_sync::<JoinHandle<std::cell::Cell<()>>>();
-        panic!("requires the `rt-core` Tokio feature flag")
+        panic!("requires the `rt` Tokio feature flag")
 
     }