isl_convex_hull.c: introduce proto_hull based on obvious facet constraints
isl_convex_hull.c: introduce proto_hull based on obvious facet constraints

proto_hull looks for for obvious facet constraints.
If any such constraints can be found, then the calling function
no longer needs to call initial_hull.

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