[Bug c++/93921] -Os generates much bigger code than -O{1,2,3,fast} for std::string::size

[bsnoksru at cisco dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93921

--- Comment #3 from Bjørnar Snoksrud <bsnoksru at cisco dot com> ---
Using '--std=c++20 -Os' generates minimal code.