There's a merged pull request on the void-packages repository

libGL: update to 19.2.1
https://github.com/void-linux/void-packages/pull/15276

Description:
In preparation for the stable release (Mesa 19.2.1)
Upstream changes that required modifications in the patches:

- `GLX_USE_TLS` was renamed into `USE_ELF_TLS`
- `3fd21a6b776e0f874e0e14d9943ac2b06bcc4aad` was merged
- `__GNU_LIBRARY__` checks were removed from `nine_debug.c` and `u_thread.c`