[Bug rtl-optimization/87096] "Optimised" snprintf is not POSIX conformant

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87096

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
I don't think we "preserve" exceptional behavior consistently.  That is, we
happily change code with exceptional behavior to code without if the main
computation result is the same.