Introduced Atomic8 and added no-barrier Atomic8 accessors.

src/atomicops_internals_x86_gcc.h

Index: src/atomicops_internals_x86_gcc.h
diff --git a/src/atomicops_internals_x86_gcc.h b/src/atomicops_internals_x86_gcc.h
index e58d598fbd4ea97cf84917bcafbde928626bfa04..1624b8238907afed62da0de405d1bd74f40909f1 100644
--- a/src/atomicops_internals_x86_gcc.h
+++ b/src/atomicops_internals_x86_gcc.h
@@ -107,6 +107,10 @@ inline Atomic32 Release_CompareAndSwap(volatile Atomic32* ptr,
   return NoBarrier_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;
 }
@@ -152,6 +156,10 @@ inline void Release_Store(volatile Atomic32* ptr, Atomic32 value) {
   // See comments in Atomic64 version of Release_Store(), below.
 }
 
+inline Atomic8 NoBarrier_Load(volatile const Atomic8* ptr) {
+  return *ptr;
+}
+
 inline Atomic32 NoBarrier_Load(volatile const Atomic32* ptr) {
   return *ptr;
 }