[Bug target/118276] memset 88 uses rep stosq while 80 uses SSE

[benfrantzdale at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118276

--- Comment #10 from Ben FrantzDale <benfrantzdale at gmail dot com> ---
I see the same codegen with `alignas(long) T a[n] = {};`:
https://godbolt.org/z/z93KEnoao