Move atomic ops and related files to base library

src/platform-posix.cc

Index: src/platform-posix.cc
diff --git a/src/platform-posix.cc b/src/platform-posix.cc
index 03ba87db741c16a80441514fb8ff9691aa18136e..e9e4161a6265c614165bc66e83111c6877c1d184 100644
--- a/src/platform-posix.cc
+++ b/src/platform-posix.cc
@@ -45,6 +45,10 @@
 #include "src/isolate-inl.h"
 #include "src/platform.h"
 
+#ifdef V8_FAST_TLS_SUPPORTED
+#include "src/base/atomicops.h"
+#endif
+
 namespace v8 {
 namespace internal {
 
@@ -599,7 +603,7 @@ static pthread_key_t LocalKeyToPthreadKey(Thread::LocalStorageKey local_key) {
 
 #ifdef V8_FAST_TLS_SUPPORTED
 
-static Atomic32 tls_base_offset_initialized = 0;
+static base::Atomic32 tls_base_offset_initialized = 0;
 intptr_t kMacTlsBaseOffset = 0;
 
 // It's safe to do the initialization more that once, but it has to be
@@ -635,7 +639,7 @@ static void InitializeTlsBaseOffset() {
     kMacTlsBaseOffset = 0;
   }
 
-  Release_Store(&tls_base_offset_initialized, 1);
+  base::Release_Store(&tls_base_offset_initialized, 1);
 }