isl_coalesce.c: coalesce_local_pair: extract out set_ineq_status_in
isl_coalesce.c: coalesce_local_pair: extract out set_ineq_status_in

This is a minor code clean-up that will make it easier to avoid
recomputing the information computed by ineq_status_in in the next commit.

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

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