anv/pipeline: Hash the entire pipeline in one go

anv/pipeline: Hash the entire pipeline in one go

Instead of hashing each stage separately (and TES and TCS together), we
hash the entire pipeline.  This means we'll get fewer cache hits if
they, for instance, re-use the same VS over and over again but it also
means we can now safely do cross-stage optimizations.

Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>