getBindGroupLayout method
The layout of one bind group, as the pipeline understood it.
Only useful where the pipeline was built with layout: "auto", and then
it is the only way to get a layout object to build a bind group against.
A backend that states its own GPUPipelineLayout never calls this — see
GPURenderPipelineDescriptor for why stating one is the better half of
that choice.
Implementation
external GPUBindGroupLayout getBindGroupLayout(int index);