[Bug c++/51270] missed warning about returning reference to temporary

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51270

--- Comment #11 from Jonathan Wakely <redi at gcc dot gnu.org> ---
It's a pity you need at least -O2 for the warnings, but I agree we can close it
as fixed.