nir: Add alignment parameters to SSBO, UBO, and shared access

nir: Add alignment parameters to SSBO, UBO, and shared access

This also changes spirv_to_nir and glsl_to_nir to set them.  The one
place that doesn't set them is shared memory access lowering in
nir_lower_io.  That will have to be updated before any consumers of it
can effectively use these new alignments.

Reviewed-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
Acked-by: Karol Herbst <kherbst@redhat.com>