reverse meaning of isl_basic_map_{less,more}_at
reverse meaning of isl_basic_map_{less,more}_at

Before, these functions were interpreted as returning maps that map elements
to elements that are less/more.
Now, they are interpreted as returning relations that express
the concept of being less/more, i.e., the elements in the domain
are now less/more than the elements in the range.

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