[Bug tree-optimization/69728] [6/7/8 Regression] internal compiler error: in outer_projection_mupa, at graphite-sese-to-poly.c:1175

[spop at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69728

--- Comment #15 from Sebastian Pop <spop at gcc dot gnu.org> ---
It makes sense to early fail when the schedule builder gets confused and built
an empty domain.  Could you please also add a comment around the if that sets
schedule_error?  The change looks good.  Thanks.