Replaces the RADV pipeline cache with an implementation
based on the common vk_pipeline_cache.
We use a dual-layer approach with two types of cache entries.
1. radv_shader:
- serialized as radv_shader_binary
- uses SHA1 of the binary as key
2. radv_pipeline_cache_object:
- contains pointers to associated radv_shaders
- serialized as list of SHA1
- uses the pipeline hash as key
In combination with single-file disk-cache, this reduces the cache size by ~60%.
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22030>
