radeonsi: implement inlinable uniforms

This improves performance for uber shaders.

It must be enabled using the new driconf option.

The driver compiles the specialized shaders in another thread without stalls,
same as all other optimizations.

Acked-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7057>
8 files changed