Use rustc_thread_pool instead of rustc-rayon-core

compiler/rustc_thread_pool/src/spawn/mod.rs

@@ -50,7 +50,7 @@ use crate::unwind;
 /// This code creates a Rayon task that increments a global counter.
 ///
 /// ```rust
-/// # use rayon_core as rayon;
+/// # use rustc_thred_pool as rayon;
 /// use std::sync::atomic::{AtomicUsize, Ordering, ATOMIC_USIZE_INIT};
 ///
 /// static GLOBAL_COUNTER: AtomicUsize = ATOMIC_USIZE_INIT;