nir,aco: CTS fixes for ACO
Mostly containing fixes for dEQP-VK.descriptor_indexing.* with ACO (which is passing completely after this MR and !2143 (merged)) but some of the changes are for other tests.
Mostly containing fixes for dEQP-VK.descriptor_indexing.* with ACO (which is passing completely after this MR and !2143 (merged)) but some of the changes are for other tests.