[Bug c++/69550] Need a way to disable "flexible array member in an otherwise empty struct" error on GCC 6

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69550

--- Comment #16 from Jonathan Wakely <redi at gcc dot gnu.org> ---
OK, given that using a zero-sized array for both members works I would say we
probably don't need to keep this open.