isl_basic_map_overlying_set: properly handle divs in model
isl_basic_map_overlying_set: properly handle divs in model

Before, we would extend the set after resetting the dimension
but before adding the divs from the model.  Any coefficients
in the divs would therefore not be copied.

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