Etnaviv Gallium3D Adds On-Disk Shader Cache Support

Etnaviv as the open-source, reverse-engineered OpenGL graphics driver for Vivante graphics IP now has support for an on-disk shader cache.

Etnaviv now has shader cache support like the other Gallium3D drivers in being able to cache shaders to disk in order to speed-up subsequent reloads of games/applications by avoiding the expensive shader recompilation process when encountering the same shaders on the same driver version.

The Etnaviv shader cache is performed along their NIR code path. Making use of the Etnaviv shader cache saves 1~2 minutes when running eEQP tests on Vivante GC2000 graphics.

This cache was merged for Mesa 20.3-devel.