[Bug c/80806] gcc does not warn if local array is memset only

[bugzilla@poradnik-webmastera.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80806

--- Comment #6 from Daniel Fruzynski <bugzilla@poradnik-webmastera.com> ---
I have checked list of my issues reported here and found Bug 68034 which is
closely related to this one. This patch probably will fix that one too, user
will know that his memset was removed by compiler.