pan/midgard: Fix recursive csel scheduling
Corner case causing invalid scheduling on shaders with nested csels, i.e. GLSL code resembling:
(foo ? bool1 : bool2) ? x : y
By explicitly disallowing csels this is fixed.
Fixes INSTR_INVALID_ENC on a glamor shader (noticeable with slowdown and visual corruption when scrolling "too far" on GTK apps).
Signed-off-by: Alyssa Rosenzweig alyssa.rosenzweig@collabora.com