[Bug c++/80472] cannot use push/pop with #pragma GCC diagnostic warning "-Wsystem-headers"

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80472

--- Comment #13 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #12)
> Improving the warning in comment 4 is irrelevant to this bug.

I've created Bug 89800 for improving that warning, please move that discussion
there.