isl_input.c: extract out common is_start_of_div
isl_input.c: extract out common is_start_of_div

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

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