Remove test_atomic.h header

Because <atomic> can now be used in C++03 there is no need for the test_atomic.h header.
This commit removes the header and converts all usages to use <atomic> instead.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@245468 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/thread/thread.condition/thread.condition.condvar/notify_one.pass.cpp

@@ -16,17 +16,17 @@
 // void notify_one();
 
 #include <condition_variable>
+#include <atomic>
 #include <mutex>
 #include <thread>
 #include <cassert>
 
-#include "test_atomic.h"
 
 std::condition_variable cv;
 std::mutex mut;
 
-AtomicInt test1(0);
-AtomicInt test2(0);
+std::atomic_int test1(0);
+std::atomic_int test2(0);
 
 void f1()
 {