Improve message when ctx is freed, but still referenced
Improve message when ctx is freed, but still referenced

Instead of a cryptic 'Assertion "ctx->ref == 0" failed' we report
'isl_ctx freed, but some objects still reference it'.

Signed-off-by: Tobias Grosser <059b8b880f8441509ec8a65b50b4c6ae74ebea76@grosser.es>
Signed-off-by: Sven Verdoolaege <e5350bbed4977f5eb8ae1dc6abd9ae59d21ace75@kotnet.org>

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