DSOAL r518 - Avoid using NULL

DSOAL r518@48151191 c++-rewrite - Avoid using NULL [2023-04-20 13:13:35 +0000]
OpenAL Soft r8515@d9fed51a master - Make sure extension functions are properly aligned on 32-bit [2023-04-13 06:39:57 +0000]
Build log: https://github.com/ThreeDeeJay/dsoal/actions/runs/10753910363/job/29823899114

Full Changelog: r511...r518