Rename RWLock to RwLock in std::sys.

library/std/src/sync/rwlock.rs

@@ -76,7 +76,7 @@ use crate::sys_common::rwlock as sys;
 /// [`Mutex`]: super::Mutex
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct RwLock<T: ?Sized> {
-    inner: sys::MovableRWLock,
+    inner: sys::MovableRwLock,
     poison: poison::Flag,
     data: UnsafeCell<T>,
 }
@@ -146,7 +146,7 @@ impl<T> RwLock<T> {
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn new(t: T) -> RwLock<T> {
         RwLock {
-            inner: sys::MovableRWLock::new(),
+            inner: sys::MovableRwLock::new(),
             poison: poison::Flag::new(),
             data: UnsafeCell::new(t),
         }