isl_basic_set_compute_vertices: set activity domain on single vertex
isl_basic_set_compute_vertices: set activity domain on single vertex

isl_basic_set_compute_vertices always sets the activity domains of
the vertices, except when there is only a single vertex.
Chnage vertices_0D to also set the activity domain in this case.

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

Meinersbur/isl,epowers/isl,simbuerg/isl,VanirLLVM/toolchain_isl,pierrotdelalune/isl,pierrotdelalune/isl,evaautomation/isl,nicolasvasilache/isl,BobSaget-Mod/libisl,epowers/isl,BenzoSM/isl,BobSaget-Mod/libisl,PollyLabs/isl,VanirLLVM/toolchain_isl,simbuerg/isl,cfx-next/toolchain_isl-upstream,tobig/isl,PollyLabs/isl,PollyLabs/isl,BenzoSM/isl,pierrotdelalune/isl,jleben/isl,tobig/isl,simbuerg/isl,KangDroidSMProject/ISL,inducer/isl-mirror,serge-sans-paille/isl,Meinersbur/isl,serge-sans-paille/isl,BobSaget-Mod/libisl,crossbuild/isl,evaautomation/isl,UBERTC/isl,UBERTC/isl,jleben/isl,jleben/isl,Meinersbur/isl,BobSaget-Mod/libisl,SaberMod/isl-current,tobig/isl,pierrotdelalune/isl,nicolasvasilache/isl,crossbuild/isl,nicolasvasilache/isl,nicolasvasilache/isl,VanirLLVM/toolchain_isl,pierrotdelalune/isl,Distrotech/isl,BenzoSM/isl,serge-sans-paille/isl,jleben/isl,abduld/isl,SaberMod/isl-current,VanirLLVM/toolchain_isl,Meinersbur/isl,inducer/isl-mirror,evaautomation/isl,simbuerg/isl,inducer/isl-mirror,KangDroidSMProject/ISL,inducer/isl-mirror,BenzoSM/isl,tobig/isl,PollyLabs/isl,Distrotech/isl,cfx-next/toolchain_isl-upstream,cfx-next/toolchain_isl-upstream,cfx-next/toolchain_isl-upstream,simbuerg/isl,epowers/isl,Distrotech/isl,evaautomation/isl,jleben/isl,SaberMod/isl-current,cfx-next/toolchain_isl-upstream,UBERTC/isl,abduld/isl,serge-sans-paille/isl,abduld/isl,KangDroidSMProject/ISL,serge-sans-paille/isl,crossbuild/isl,epowers/isl,KangDroidSMProject/ISL,Distrotech/isl,PollyLabs/isl,KangDroidSMProject/ISL,inducer/isl-mirror,nicolasvasilache/isl,BenzoSM/isl,VanirLLVM/toolchain_isl,SaberMod/isl-current,abduld/isl,epowers/isl,crossbuild/isl,UBERTC/isl,BobSaget-Mod/libisl,Distrotech/isl