Draft: vulkan/runtime,radv/rt: Use GFX11 pointer flags

AMD hardware can early-cull box nodes if all leaves are either opaque or not and the ray flags are set to discard (non-)opaque geometries. This works even across TLAS/BLAS boundaries.

Propagate info on whether all child nodes are opaque or not through the BVH to allow RADV to set these flags per box node.

Then, enable pointer flags on RADV/gfx11 in the BVH descriptor and pass the ray flags through to the intersection instruction.

Based on !31433 (merged) because that one deserves to land first before more BVH builder modifications come :P

Draft because of this, and because more perf testing is needed if it might regress things somewhere right now.