st/mesa: determine states used or affected by shaders at compile time

st/mesa: determine states used or affected by shaders at compile time

At compile time, each shader determines which ST_NEW flags should be set
at shader bind time.

This just sets the new field for all shaders. The next commit will use it.

v2: small code unification

Tested-by: Edmondo Tommasina <edmondo.tommasina@gmail.com>
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com> (v1)