isl_qpolynomial_lift: fix lifting in absence of divs
isl_qpolynomial_lift: fix lifting in absence of divs

If there are no divs, then we still need to modify the (zero row)
div matrix to make sure that the number of columns remains consistent.

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