isl_convex_hull.c: explicitly mark wrapping lp problem as rational
isl_convex_hull.c: explicitly mark wrapping lp problem as rational

This shouldn't have any effect at the moment, but in future we may
want to be more aggressive on non-rational tableau.

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

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