[Bug tree-optimization/70614] [4.9/5/6 Regression] GCC gets stuck with -O

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70614

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
And I already removed the quadraticness there!  In an original version of the
patch I only looked at BIVs but that regressed sth.  See PR67783.