Introduced Atomic8 and added no-barrier Atomic8 accessors.

src/atomicops_internals_mac.h

Index: src/atomicops_internals_mac.h
diff --git a/src/atomicops_internals_mac.h b/src/atomicops_internals_mac.h
index 4bd0c09bdfd4032970597540ac8f96a8156de2ad..80647f77fab137e4d8982d8b8a6d9d3992cb1f7c 100644
--- a/src/atomicops_internals_mac.h
+++ b/src/atomicops_internals_mac.h
@@ -93,6 +93,10 @@ inline Atomic32 Release_CompareAndSwap(volatile Atomic32* ptr,
   return Acquire_CompareAndSwap(ptr, old_value, new_value);
 }
 
+inline void NoBarrier_Store(volatile Atomic8* ptr, Atomic8 value) {
+  *ptr = value;
+}
+
 inline void NoBarrier_Store(volatile Atomic32* ptr, Atomic32 value) {
   *ptr = value;
 }
@@ -107,6 +111,10 @@ inline void Release_Store(volatile Atomic32* ptr, Atomic32 value) {
   *ptr = value;
 }
 
+inline Atomic8 NoBarrier_Load(volatile const Atomic8* ptr) {
+  return *ptr;
+}
+
 inline Atomic32 NoBarrier_Load(volatile const Atomic32* ptr) {
   return *ptr;
 }