isl_union_*_subtract_domain: use isl_union_*_transform
isl_union_*_subtract_domain: use isl_union_*_transform

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

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