[Bug tree-optimization/68021] [6 Regression] ice in rewrite_use_nonlinear_expr with -O3

[ysrumyan at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68021

--- Comment #3 from Yuri Rumyantsev <ysrumyan at gmail dot com> ---
It looks like unswitching of outer loops pass simply triggers the issue and
this tree-ssa-loop-ivopts issue.