[Bug libstdc++/77264] [7 Regression] std::string's replace gives wrong results with C++17, works with C++11

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77264

--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> ---
The patch at https://gcc.gnu.org/ml/gcc-patches/2016-08/msg01179.html would fix
it, but I'll wait a bit to see if the committee agrees with that solution.