privately export isl_schedule_node_gist
privately export isl_schedule_node_gist

This will make it easier to reuse this function from another
function that appears before its definition in the next commit,
without having to move around any code.

Signed-off-by: Sven Verdoolaege <e5350bbed4977f5eb8ae1dc6abd9ae59d21ace75@kotnet.org>

BenzoSM/isl,BenzoSM/isl,nicolasvasilache/isl,Distrotech/isl,Distrotech/isl,UBERTC/isl,tobig/isl,UBERTC/isl,BenzoSM/isl,Meinersbur/isl,UBERTC/isl,inducer/isl-mirror,UBERTC/isl,inducer/isl-mirror,Meinersbur/isl,tobig/isl,inducer/isl-mirror,PollyLabs/isl,Distrotech/isl,BenzoSM/isl,Meinersbur/isl,PollyLabs/isl,nicolasvasilache/isl,Distrotech/isl,PollyLabs/isl,Meinersbur/isl,PollyLabs/isl,PollyLabs/isl,nicolasvasilache/isl,nicolasvasilache/isl,BenzoSM/isl,tobig/isl,nicolasvasilache/isl,inducer/isl-mirror,inducer/isl-mirror,Distrotech/isl,tobig/isl