[Bug tree-optimization/70546] ifconvert if(cond) ++count; to count += cond; fails because of mergephi and failed loop header copying

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70546

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I think this is a dup of bug 30521.