[Bug tree-optimization/105651] [12/13 Regression] bogus "may overlap" memcpy warning with std::string and operator+ at -O3

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105651

--- Comment #20 from Richard Biener <rguenth at gcc dot gnu.org> ---
See also https://gcc.gnu.org/pipermail/gcc-patches/2022-July/598839.html
and https://gcc.gnu.org/pipermail/gcc-patches/2022-July/598840.html
which I didn't pursue further since they didn't seem to catch the case
reliably.