Regenerate sources - Githubissues

This is just following up on #89, updating sources after an update to a .gyb file.

[X] I've read the Contribution Guidelines
[X] My contributions are licensed under the Swift license.
[ ] I've followed the coding style of the rest of the project.
[ ] I've added tests covering all new code paths my change adds to the project (if appropriate).
[ ] I've verified that my change does not break any existing tests.
[ ] I've updated the documentation if necessary.

apple / swift-atomics