Add LLVM's unordered intrinsic to Rust.

Author: pythonesque

src/libcore/intrinsics.rs

@@ -77,10 +77,12 @@ extern "rust-intrinsic" {
     pub fn atomic_load<T>(src: *const T) -> T;
     pub fn atomic_load_acq<T>(src: *const T) -> T;
     pub fn atomic_load_relaxed<T>(src: *const T) -> T;
+    pub fn atomic_load_unordered<T>(src: *const T) -> T;
 
     pub fn atomic_store<T>(dst: *mut T, val: T);
     pub fn atomic_store_rel<T>(dst: *mut T, val: T);
     pub fn atomic_store_relaxed<T>(dst: *mut T, val: T);
+    pub fn atomic_store_unordered<T>(dst: *mut T, val: T);
 
     pub fn atomic_xchg<T>(dst: *mut T, src: T) -> T;
     pub fn atomic_xchg_acq<T>(dst: *mut T, src: T) -> T;

src/librustc_trans/trans/intrinsic.rs

@@ -518,6 +518,7 @@ pub fn trans_intrinsic_call<'a, 'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
                 llvm::SequentiallyConsistent
             } else {
                 match split[2] {
+                    "unordered" => llvm::Unordered,
                     "relaxed" => llvm::Monotonic,
                     "acq"     => llvm::Acquire,
                     "rel"     => llvm::Release,