On macOS 26, some of the math for setting the index buffer length
draw register is missing for indirect draws, resulting in robustness
failures. Work around this by handling robustness ourselves.
On macOS 26 and 27 beta, index robustness does not work for buffers
that are not 32-bit aligned. Handle these ourselves.
Reviewed-by: Aitor Camacho <aitor@lunarg.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/42354>
dec456d02e