gallium: add a resource flag to say no over allocation.

llvmpipe overallocates buffers for buffers used as render targets,
however this breaks some vulkan apps (UE4), so add a workaround
flag to force llvmpipe to not overallocate certain buffers.

Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6082>
1 file changed