stabilize atomics (now atomic)

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, 1 insertions, 1 deletions

diff --git a/src/libsync/mpmc_bounded_queue.rs b/src/libsync/mpmc_bounded_queue.rs
index d54186dc221..949ef3bc34c 100644
--- a/src/libsync/mpmc_bounded_queue.rs
+++ b/src/libsync/mpmc_bounded_queue.rs
@@ -37,7 +37,7 @@ use collections::Vec;
 use core::num::next_power_of_two;
 use core::cell::UnsafeCell;
 
-use atomics::{AtomicUint,Relaxed,Release,Acquire};
+use atomic::{AtomicUint,Relaxed,Release,Acquire};
 
 struct Node<T> {
     sequence: AtomicUint,