Fix phpGH-16849: Error dialog causes process to hang

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 phpGH-16850.

Author: cmb69