dav1d 0.9.0 'Golden Eargle' the fast and lean AV1 decoder

0.9.0 is a major version of dav1d, adding notably 10b acceleration on x86-64.

This release adds acceleration in SIMD for most functions in 10b and 12b.
The SIMD written is for AVX2 chips, running in 64b.

This release continues the ARM optimizations, with FilmGrain implemented
for ARM64 processors.