[Development] QtCore missing check for memory allocation

[Alex Montgomery]

> Note that we're talking about a standard violation in the first place. The
> standard says you can replace operator new, so if MSVC doesn't allow you to do
> it properly, then you can throw the standard out of the window. If an inline
> operator new (for MSVC only) solved the problem, it would be ok.

As in, you'd be ok with individuals locally hacking Qt to work this
way, or as in you'd be ok with including a mechanism in a future
version of Qt to replace new and delete that (on Windows only) used
this methodology?