Import the 2021 prelude in the core crate

library/core/src/array/equality.rs

@@ -1,5 +1,4 @@
 use crate::cmp::BytewiseEq;
-use crate::convert::TryInto;
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T, U, const N: usize> PartialEq<[U; N]> for [T; N]

library/core/src/array/mod.rs

@@ -6,7 +6,7 @@
 
 use crate::borrow::{Borrow, BorrowMut};
 use crate::cmp::Ordering;
-use crate::convert::{Infallible, TryFrom};
+use crate::convert::Infallible;
 use crate::error::Error;
 use crate::fmt;
 use crate::hash::{self, Hash};