* [ASTraitCollection] Convert ASPrimitiveTraitCollection from lock to atomic.
This resolves a deadlock case: https://github.com/TextureGroup/Texture/issues/353
* [ASTraitCollection] Use assignment operator instead of .store() for C++ atomic.
* no message
* Go further
* Make the symbols public so that apps actually build
* Move ASAvailability into the umbrella header
* Remove duplicate define
* Put the file back where it was in the list
* Revert "Put the file back where it was in the list"
This reverts commit 6a80c15b5b5efe5ff39812a018114e8bdc1dc0cf.
