glsl: Override the # of varying slots for ClipDistance and TessLevel*.
glsl: Override the # of varying slots for ClipDistance and TessLevel*.

Right now, this shouldn't have any effect, as all drivers use
LowerClipDist and LowerTessFactors to turn the float[] arrays into
vectors.

However, it should help make it possible for drivers to avoid that
lowering.

Signed-off-by: Kenneth Graunke <bd2562f754ec92342f93f61c25d731e290a2ffa8@whitecape.org>
Reviewed-by: Jason Ekstrand <68c46a606457643eab92053c1c05574abb26f861@jlekstrand.net>
Reviewed-by: Timothy Arceri <5dd83789ef3714029244367ba1ca09f1d7627408@collabora.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler