nir_lower_explicit_io generates mul+add chains even for constants. One round of constant folding should get rid of these. This fixes all of the dEQP-VK.glsl.conversions.* tests on panvk.
nir_lower_explicit_io generates mul+add chains even for constants. One round of constant folding should get rid of these. This fixes all of the dEQP-VK.glsl.conversions.* tests on panvk.