initial import of mesa 21.3.7

main changes since 19.1.7 include:
- more support for Vulkan functions
- better supported for newer radeonsi (both amdgpu and radeon backends)
- various bug fixes in many drivers
- many fixes and enhancements for intel drivers
- some fixes for nvidia
- OpenGL 4.6 for some drivers (intel, radeonsi)
- intel Tigerlake and Rocketlake support
- Vulkan 1.2 for some drivers
- OpenGL 4.5, GLES 3.2, and more on llvmpipe
- working Panfrost and Midgard drivers
- fix warnings in radeonsi vs newer llvm

from maya:

Import mesa 18.3.4.

Mesa 18.3.4 implements the OpenGL 4.5 API.
Some drivers don't support all the features required in OpenGL 4.5.

merge Mesa 10.3.5.

initial import of MesaLib-10.3.5

merge MesaLib 7.11.2

import Mesa 7.8.2, lib part. major changes since 7.7.1:
- several new extensions for various drivers
- many i965, i915 driver fixes
- many glsl fixes

initial import of MesaLib-7.7.1

initial import of MesaLib-7.4.2

initial import of MesaLib-7.0.3