Reland Update implementation of atomics with latest Chromium version but use compiler builtin atomi…

src/base/atomicops_internals_atomicword_compat.h

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file is an internal atomic implementation, use atomicops.h instead.
 
 #ifndef V8_BASE_ATOMICOPS_INTERNALS_ATOMICWORD_COMPAT_H_
 #define V8_BASE_ATOMICOPS_INTERNALS_ATOMICWORD_COMPAT_H_
 
 // AtomicWord is a synonym for intptr_t, and Atomic32 is a synonym for int32,
@@ skipping 49 matching lines @@
                                          AtomicWord new_value) {
   return v8::base::Release_CompareAndSwap(
       reinterpret_cast<volatile Atomic32*>(ptr), old_value, new_value);
 }
 
 inline void NoBarrier_Store(volatile AtomicWord *ptr, AtomicWord value) {
   NoBarrier_Store(
       reinterpret_cast<volatile Atomic32*>(ptr), value);
 }
 
-inline void Acquire_Store(volatile AtomicWord* ptr, AtomicWord value) {
-  return v8::base::Acquire_Store(
-      reinterpret_cast<volatile Atomic32*>(ptr), value);
-}
-
 inline void Release_Store(volatile AtomicWord* ptr, AtomicWord value) {
   return v8::base::Release_Store(
       reinterpret_cast<volatile Atomic32*>(ptr), value);
 }
 
 inline AtomicWord NoBarrier_Load(volatile const AtomicWord *ptr) {
   return NoBarrier_Load(
       reinterpret_cast<volatile const Atomic32*>(ptr));
 }
 
 inline AtomicWord Acquire_Load(volatile const AtomicWord* ptr) {
   return v8::base::Acquire_Load(
       reinterpret_cast<volatile const Atomic32*>(ptr));
 }
 
-inline AtomicWord Release_Load(volatile const AtomicWord* ptr) {
-  return v8::base::Release_Load(
-      reinterpret_cast<volatile const Atomic32*>(ptr));
-}
-
 }  // namespace base
 }  // namespace v8
 
 #endif  // !defined(V8_HOST_ARCH_64_BIT)
 
 #endif  // V8_BASE_ATOMICOPS_INTERNALS_ATOMICWORD_COMPAT_H_