nvc0: Add shader disk caching

nvc0: Add shader disk caching

Adds shader disk caching for nvc0 to reduce the need to every time compile
shaders. Shaders are saved into disk_shader_cache from nvc0_screen structure.

It serializes the input nv50_ir_prog_info to compute the hash key and
also to do a byte compare between the original nv50_ir_prog_info and the one
saved in the cache. If keys match and also the byte compare returns they
are equal, shaders are same, and the compiled nv50_ir_prog_info_out from the
cache can be used instead of compiling input info.

Seems to be significantly improving loading times, these are the results
from running bunch of shaders:
cache off
real	2m58.574s
user	21m34.018s
sys	0m8.055s

cache on, first run
real	3m32.617s
user	24m52.701s
sys	0m20.400s

cache on, second run
real	0m23.745s
user	2m43.566s
sys	0m4.532s

Signed-off-by: Mark Menzynski <mmenzyns@redhat.com>
Reviewed-by: Karol Herbst <kherbst@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4264>