Revert "Add new atomic operations and use them in two places."

runtime/vm/atomic_linux.h

Index: runtime/vm/atomic_linux.h
diff --git a/runtime/vm/atomic_linux.h b/runtime/vm/atomic_linux.h
index 18c44241a2da4837c409014fbc3155c7166ad61c..18456cf57d3330280e827e91b79dd5d2266f31c8 100644
--- a/runtime/vm/atomic_linux.h
+++ b/runtime/vm/atomic_linux.h
@@ -15,15 +15,6 @@
 
 namespace dart {
 
-template<typename T> T AtomicOperations::LoadAcquire(T* ptr) {
-  return __atomic_load_n(ptr, __ATOMIC_ACQUIRE);
-}
-
-
-template<typename T> void AtomicOperations::StoreRelease(T* ptr, T val) {
-  __atomic_store_n(ptr, val, __ATOMIC_RELEASE);
-}
-
 
 inline uintptr_t AtomicOperations::FetchAndIncrement(uintptr_t* p) {
   return __sync_fetch_and_add(p, 1);