mesa/st: add special casing for pointsize constant updating during validate
the previous method of using affected_states to trigger constant updates was ineffectual in the scenario where a ubo pointsize was needed on the first time a non-precompiled shader was used after being the not-last vertex stage:
- have vs+gs -> gs precompiles with pointsize lowering -> gs constants get updated
- remove gs -> vs was precompiled without pointsize lowering -> vs constants broken
now just do a quick check as in st_atom_shader.c and set the flag manually to ensure the update is done correctly every time
cc: mesa-stable
fixes #6207 (closed)
fixes (radv): KHR-GL46.texture_cube_map_array.image_op_fragment_sh KHR-GL46.texture_cube_map_array.sampling KHR-GL46.texture_cube_map_array.texture_size_fragment_sh KHR-GL46.constant_expressions*