Rollup merge of #23329 - jbcrail:rm-syntax-highlight, r=sanxiyn

 As suggested by @steveklabnik in #23254, I removed the redundant Rust syntax highlighting from the documentation.

4 files changed, 6 insertions, 6 deletions

diff --git a/src/libstd/sync/barrier.rs b/src/libstd/sync/barrier.rs
index f697d10d5df..ebf4d337749 100644
--- a/src/libstd/sync/barrier.rs
+++ b/src/libstd/sync/barrier.rs
@@ -13,7 +13,7 @@ use sync::{Mutex, Condvar};
 /// A barrier enables multiple tasks to synchronize the beginning
 /// of some computation.
 ///
-/// ```rust
+/// ```
 /// use std::sync::{Arc, Barrier};
 /// use std::thread;
 ///
diff --git a/src/libstd/sync/mutex.rs b/src/libstd/sync/mutex.rs
index 41378a6b312..1cbfbbf2927 100644
--- a/src/libstd/sync/mutex.rs
+++ b/src/libstd/sync/mutex.rs
@@ -46,7 +46,7 @@ use fmt;
 ///
 /// # Examples
 ///
-/// ```rust
+/// ```
 /// use std::sync::{Arc, Mutex};
 /// use std::thread;
 /// use std::sync::mpsc::channel;
@@ -84,7 +84,7 @@ use fmt;
 ///
 /// To recover from a poisoned mutex:
 ///
-/// ```rust
+/// ```
 /// use std::sync::{Arc, Mutex};
 /// use std::thread;
 ///
@@ -135,7 +135,7 @@ unsafe impl<T: Send> Sync for Mutex<T> { }
 ///
 /// # Examples
 ///
-/// ```rust
+/// ```
 /// use std::sync::{StaticMutex, MUTEX_INIT};
 ///
 /// static LOCK: StaticMutex = MUTEX_INIT;
diff --git a/src/libstd/sync/once.rs b/src/libstd/sync/once.rs
index 5cad2916624..258cf1d38a8 100644
--- a/src/libstd/sync/once.rs
+++ b/src/libstd/sync/once.rs
@@ -26,7 +26,7 @@ use sync::{StaticMutex, MUTEX_INIT};
 ///
 /// # Examples
 ///
-/// ```rust
+/// ```
 /// use std::sync::{Once, ONCE_INIT};
 ///
 /// static START: Once = ONCE_INIT;
diff --git a/src/libstd/sync/task_pool.rs b/src/libstd/sync/task_pool.rs
index 3d31790550b..8a1946b86ab 100644
--- a/src/libstd/sync/task_pool.rs
+++ b/src/libstd/sync/task_pool.rs
@@ -60,7 +60,7 @@ impl<'a> Drop for Sentinel<'a> {
 ///
 /// # Examples
 ///
-/// ```rust
+/// ```
 /// use std::sync::TaskPool;
 /// use std::iter::AdditiveIterator;
 /// use std::sync::mpsc::channel;