spirv: Handle tessellation execution modes.
spirv: Handle tessellation execution modes.

v2: Use info->tess.
v3: Handle more things in either TCS/TES.

Signed-off-by: Kenneth Graunke <bd2562f754ec92342f93f61c25d731e290a2ffa8@whitecape.org>
Reviewed-by: Dave Airlie <f2295d84e358395675bc8031be58672073ae065e@redhat.com> [v1]
Reviewed-by: Iago Toral Quiroga <a847aabaac44184372f6b1cd1a59aa254daaeb0b@igalia.com> [v1]
Reviewed-by: Jason Ekstrand <68c46a606457643eab92053c1c05574abb26f861@jlekstrand.net>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler