dzn: Cache pipeline info

dzn: Cache pipeline info

We are already caching DXIL shaders individually, but that forces us
to retrieve the NIR shader, do the linking and binding translation
steps, to finally query the cache for each DXIL shader. This pipeline
caching is about skipping those steps when we can.

Note that a graphics/compute pipeline cache entry doesn't contain the
DXIL shaders, but hashes to retrieve those shaders from the same cache.

Reviewed-by: Jesse Natalie <jenatali@microsoft.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17140>