If `_DEBUG` is set, assertion failures and errors are directed to a
debug message window by default[1]. That causes a process to hang,
since these dialogs are modal. While we already cater to assertion
failures, errors have apparently been overlooked.
We choose a minimal fix for BC reasons; although passing `0` as
`reportMode` is undocumented, it obviously works fine for a long time.
We may consider to improve on this for the `master` branch.
[1] <https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/crtsetreportmode>
Closes GH-16850.
Christoph M. Becker
e75061b512