pan/bi: Drop 64-bit constant support

We don't support 64-bit clauses and don't intend to (v6 only, v7 doesn't
support them) so this is irrelevant.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7206>
1 file changed