[Bug tree-optimization/80794] constant objects can be assumed to be immutable

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80794

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Can't S::f call inplace operator new changing the value of *this for the call
in bar?