isl_basic_map_from_constraint: keep all divs, even redundant ones
isl_basic_map_from_constraint: keep all divs, even redundant ones

When this function is called by CLooG, it assumes that the position
of the divs will remain the same.  If the redundant divs are removed,
then this may not be the case.
We should probably try to come up with a more robust interface.

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