winsys/amdgpu: Enlarge const IB size.

Necessary to prevent performance regressions due to extra flushing.

Probably should enlarge it even further when also updating
uniforms through the CE, but this seems large enough for now.

v2: Add preamble IB.

Signed-off-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
1 file changed