Auto merge of #1068 - RalfJung:uprust, r=RalfJung

rustup for never stabilization

rust-version

@@ -1 +1 @@
-b9cf5417892ef242c783ef963deff5436205b0f6
+bd816fd76f4f7a040ca7ac8ca5bc556d761f96fa

tests/compile-fail/never_say_never.rs

@@ -1,7 +1,6 @@
 // This should fail even without validation
 // compile-flags: -Zmiri-disable-validation
 
-#![feature(never_type)]
 #![allow(unreachable_code)]
 
 fn main() {

tests/compile-fail/never_transmute_humans.rs

@@ -1,8 +1,6 @@
 // This should fail even without validation
 // compile-flags: -Zmiri-disable-validation
 
-#![feature(never_type)]
-
 struct Human;
 
 fn main() {

tests/compile-fail/never_transmute_void.rs

@@ -1,7 +1,6 @@
 // This should fail even without validation
 // compile-flags: -Zmiri-disable-validation
 
-#![feature(never_type)]
 #![allow(unused, invalid_value)]
 
 enum Void {}

tests/run-pass/async-fn.rs

@@ -1,5 +1,3 @@
-#![feature(never_type)]
-
 use std::{future::Future, pin::Pin, task::Poll, ptr};
 use std::task::{Waker, RawWaker, RawWakerVTable, Context};
 

tests/run-pass/generator.rs

@@ -1,4 +1,4 @@
-#![feature(generators, generator_trait, never_type)]
+#![feature(generators, generator_trait)]
 
 use std::ops::{GeneratorState, Generator};
 use std::pin::Pin;

tests/run-pass/loop-break-value.rs

@@ -1,4 +1,3 @@
-#![feature(never_type)]
 #![allow(unreachable_code)]
 
 #[allow(unused)]