Since #4048 enabled robustBufferAccess2, AMD's Windows driver draws
nothing in agc_driver_layered_volume_draw and agc_driver_layered_volume_vertex,
and the selected loads make the high half of agc_driver_subvector_loop's
wave64 skip its loop. Until the cause is found, that driver does not get
the feature, and its loads keep their selections.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
