[Bug ipa/81128] Function multi-versioning does not work with -O

[nathan at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81128

--- Comment #6 from Nathan Sidwell <nathan at gcc dot gnu.org> ---
the ifunc attribute is essentially slightly different syntactic sugar to the
alias attribute.  It sounds like the optimizer is treating the attribute as-if
it were an alias.