[Bug rtl-optimization/84878] ICE: Segmentation fault (in add_cross_iteration_register_deps)

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84878

--- Comment #6 from Peter Bergner <bergner at gcc dot gnu.org> ---
(In reply to Peter Bergner from comment #5)
> ICEs on GCC 7 but not with GCC 6.

Backport to GCC 7 bootstraps and regtests with no regressions.  Waiting for
approval to commit it to the GCC 7 branch.