isl_union_map_params: plug memory leak in case of empty input
isl_union_map_params: plug memory leak in case of empty input

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

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