[Bug libstdc++/99181] char_traits (and thus string_view) compares strings differently in constexpr and non-constexpr contexts

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99181

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
We're in namespace std here so size_t doesn't need to be qualified, but
otherwise the patch is fine.