[Bug c/120353] Flex array struct referenced in the middle via type alias of forward declaration is not reported by -Wflex-array-member-not-at-end option

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120353

--- Comment #9 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to qinzhao from comment #8)
> > I'd say so, unless other RMs disagree.
> sure, I will revert it.

I've missed that Joseph acked the backport and that the warning isn't enabled
under either -Wall or -Wextra, so perhaps I can live with it staying on the
branch.