[Bug tree-optimization/71815] SLSR misses several PHI candidate cases

[wschmidt at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71815

--- Comment #6 from Bill Schmidt <wschmidt at gcc dot gnu.org> ---
Actually, it looks like a similar problem for the unknown stride case.  Again
there is logic that relies on single-reached-use for determining what
expressions go dead.  We need to factor in expressions that go dead conditional
on other expressions going dead.  I'll work on a solution.