Previously this wasn't a problem. However, with the new API update,
descriptor sets can now be sparse so the client doesn't have to provide an
entry for every binding. This means that it's possible for a binding to be
uninitialized other than the memset. In that case, we want to have a null
array of immutable samplers.
This made for an unfortunately large amount of work since we were using it
fairly heavily internally. However, gl_shader_stage does basically the
same things, so it's not too bad.
The stuff to take descriptor sets and turn them into binding tables and
sampler tables is still in anv_cmd_buffer.c. We may want to consider
putting it in anv_descriptor_set.c eventually.
Jason Ekstrand
BogDan Vatra
Kristian Høgsberg Kristensen