aco: Optimize out trivial code from uniform bools.

This should remove most of the excess code size that was
introduced by making all booleans per-lane.

Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Reviewed-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>