radv,aco: decouple shader_info/options from radv_shader_args
This gets rid of another mess.
Next step is to configure the RSRC shader fields directly from the shader arguments. It's the same idea as declaring the user SGPR locations from the shader arguments. It will be more robust and will avoid using uninitialized VGPR inputs for free.
Another following step is to move the user SGPR locations out of radv_shader_info to constify it (cf. radv_shader_binary_info).