[Bug c/120354] Flexible array union in the middle is not reported by -Wflex-array-member-not-at-end option when flexible array member is not the last one

[alansnape3058 at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120354

--- Comment #1 from Ella Ma <alansnape3058 at gmail dot com> ---
Details and comparison with Clang in https://godbolt.org/z/h8qYhK6rY