[Mesa-dev] More shader state clean-ups

[Timothy Arceri]

This series applies on top of my series to rework the way we
handle the gl shader/program structs [1].

These changes allow us to stop passing duplicate fields around
for no good reason, and allow us to simplify the on disk shader 
cache by getting all the values from a single location we can
cache less.

[1] https://lists.freedesktop.org/archives/mesa-dev/2016-November/135916.html