[Bug libstdc++/125693] std::vector::insert(it, cref) crashes when sizeof(value_type) ≥ 8MiB

[marc.mutz at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125693

--- Comment #1 from Marc Mutz <marc.mutz at hotmail dot com> ---
I should add that, of course, the Qt test only "works", because nothing is ever
put into the QList. If I run the test in the OP with QList<LargerThanStack>,
already the first emplace_back() blows up.