rollup merge of #20519: ville-h/rwlock-rename

Conflicts:
	src/libstd/sync/rwlock.rs

Author: alexcrichton

src/libstd/sync/mod.rs

@@ -22,8 +22,8 @@ pub use core::atomic;
 
 pub use self::mutex::{Mutex, MutexGuard, StaticMutex};
 pub use self::mutex::MUTEX_INIT;
-pub use self::rwlock::{RWLock, StaticRWLock, RWLOCK_INIT};
-pub use self::rwlock::{RWLockReadGuard, RWLockWriteGuard};
+pub use self::rwlock::{RwLock, StaticRwLock, RW_LOCK_INIT};
+pub use self::rwlock::{RwLockReadGuard, RwLockWriteGuard};
 pub use self::condvar::{Condvar, StaticCondvar, CONDVAR_INIT};
 pub use self::once::{Once, ONCE_INIT};
 pub use self::semaphore::{Semaphore, SemaphoreGuard};

src/libstd/sync/poison.rs

@@ -49,7 +49,7 @@ pub struct Guard {
 
 /// A type of error which can be returned whenever a lock is acquired.
 ///
-/// Both Mutexes and RWLocks are poisoned whenever a task fails while the lock
+/// Both Mutexes and RwLocks are poisoned whenever a task fails while the lock
 /// is held. The precise semantics for when a lock is poisoned is documented on
 /// each lock, but once a lock is poisoned then all future acquisitions will
 /// return this error.