[Bug tree-optimization/88775] [8/9 Regression] Optimize std::string assignment

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88775

--- Comment #11 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 45405
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=45405&action=edit
gcc9-pr88775.patch

Full patch.