[Bug c/98055] __builtin_alloca should not have warn_unused_result attribute

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98055

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
See the thread starting at:
https://gcc.gnu.org/pipermail/gcc-patches/2019-June/523700.html