[Bug libstdc++/89090] vector.tcc uses "if constexpr" in C++11 mode

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89090

--- Comment #8 from Jonathan Wakely <redi at gcc dot gnu.org> ---
That doesn't work. I don't get to control every G++ users' build system.