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

[jakub at gcc dot gnu.org]

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

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Bence Szabó from comment #4)
> As a remark for 'same code with -std=c++14 and -std=c++17 here', I can
> confirm, the example you provided also produces same assembly for me in
> c++14 and c++17.
> Also compiling t032 with only c++14 or only c++17 still results in a failing
> test case (30.71) and then a crash. Maybe this is not the same abi problem?

Ah, then it is not c++14 vs. c++17 ABI incompatibility, but some bug in va_arg
passing of such classes for mingw.