auto merge of #16258 : aturon/rust/stabilize-atomics, r=alexcrichton

This commit stabilizes the `std::sync::atomics` module, renaming it to
`std::sync::atomic` to match library precedent elsewhere, and tightening
up behavior around incorrect memory ordering annotations.

The vast majority of the module is now `stable`. However, the
`AtomicOption` type has been deprecated, since it is essentially unused
and is not truly a primitive atomic type. It will eventually be replaced
by a higher-level abstraction like MVars.

Due to deprecations, this is a:

[breaking-change]

1 files changed, 7 insertions, 1 deletions

diff --git a/src/libstd/sync/mod.rs b/src/libstd/sync/mod.rs
index cc32818baa4..1d189f8d4bc 100644
--- a/src/libstd/sync/mod.rs
+++ b/src/libstd/sync/mod.rs
@@ -17,12 +17,18 @@
 
 #![experimental]
 
-pub use core_sync::{atomics, deque, mpmc_bounded_queue, mpsc_queue, spsc_queue};
+#[stable]
+pub use core_sync::atomic;
+
+pub use core_sync::{deque, mpmc_bounded_queue, mpsc_queue, spsc_queue};
 pub use core_sync::{Arc, Weak, Mutex, MutexGuard, Condvar, Barrier};
 pub use core_sync::{RWLock, RWLockReadGuard, RWLockWriteGuard};
 pub use core_sync::{Semaphore, SemaphoreGuard};
 pub use core_sync::one::{Once, ONCE_INIT};
 
+#[deprecated = "use atomic instead"]
+pub use atomics = core_sync::atomic;
+
 pub use self::future::Future;
 pub use self::task_pool::TaskPool;