Test default layout bind group binding.

According to the current WebGPU spec, a bind group created
with a bind group layout that itself is from a default layout
pipeline (a pipeline created with `layout: 'auto'` is
incompatible with any other bind group created with a different
bind group layout, even if they'd appear to match by their
resource types and binding locations. Further, no excpetion is made
for empty bind groups.