We shouldn't potentially override stuff in the std library and this allows us to map directly to __ATOMIC_* memory orders which is more correct.
Signed-off-by: Joshua Ashton <joshua@froggi.es>
There is no stdatomic available on MSVC so let's clean things up.
This moves all the atomic helpers to vkd3d_atomic.h and implements all platform's spinlocks in entirely the same way.
Signed-off-by: Joshua Ashton <joshua@froggi.es>