[Bug middle-end/123801] [13/14/15/16 Regression] Wstringop-overflow false positive since r12-4240

[siddhesh at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123801

--- Comment #14 from Siddhesh Poyarekar <siddhesh at gcc dot gnu.org> ---
OK, so any pointer that points into the middle of an object, which can be
replaced with a different element will cause this.  That would be structs and
unions both, not just unions.