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
The test class 'G' reads and writes to the same static variables in its
constructor, destructor and call operator. When threads are
constructed using `std::thread t((G()))` there is a race condition between the
destruction of the temporary and the execution of `G::operator()()`.
The fix is to simply create the input before creating the thread.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@233946 91177308-0d34-0410-b5e6-96231b3b80d8
