spirv, radv, anv: Replace ptr_type with addr_format

spirv, radv, anv: Replace ptr_type with addr_format

Instead of setting the glsl types of the pointers for each resource,
set the nir_address_format, from which we can derive the glsl_type,
and in the future the bit pattern representing a NULL pointer.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>