Move atomic ops and related files to base library

src/base/atomicops_internals_mips_gcc.h

 // Copyright 2010 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_ATOMICOPS_INTERNALS_MIPS_GCC_H_
-#define V8_ATOMICOPS_INTERNALS_MIPS_GCC_H_
+#ifndef V8_BASE_ATOMICOPS_INTERNALS_MIPS_GCC_H_
+#define V8_BASE_ATOMICOPS_INTERNALS_MIPS_GCC_H_
 
 namespace v8 {
-namespace internal {
+namespace base {
 
 // Atomically execute:
 //      result = *ptr;
 //      if (*ptr == old_value)
 //        *ptr = new_value;
 //      return result;
 //
 // I.e., replace "*ptr" with "new_value" if "*ptr" used to be "old_value".
 // Always return the old value of "*ptr"
 //
@@ skipping 125 matching lines @@
   Atomic32 value = *ptr;
   MemoryBarrier();
   return value;
 }
 
 inline Atomic32 Release_Load(volatile const Atomic32* ptr) {
   MemoryBarrier();
   return *ptr;
 }
 
-} }  // namespace v8::internal
+} }  // namespace v8::base
 
-#endif  // V8_ATOMICOPS_INTERNALS_MIPS_GCC_H_
+#endif  // V8_BASE_ATOMICOPS_INTERNALS_MIPS_GCC_H_