[Bug target/94770] class with empty base passed incorrectly with -std=c++17 on mingw

[sbence92 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94770

--- Comment #2 from Bence Szabó <sbence92 at gmail dot com> ---
Yes there's a T(30,struct{}a[1];,) in t032.
Indeed the fail happens on a variadic function (void check30va(int i, ...)).

I dig in some more and it turns out all the tests listed crash. I've attached
the formated preprocessed source for t032.