[Development] Broken RNG on AMD Ryzen CPUs affect QTemporaryFile, Qt IFW

[Cristian Adam]

> >
> > Judging from the screenshots, it's the latest and greatest version of
> > the Qt installer (qt-opensource-windows-x86-5.14.1.exe) [1]
> 
> Okay, but what version of Qt is the Qt Installer using? Installer team, can you
> check?
> 

Looking into the binary I've found:

"Build date: Jan  8 2020 IFW Version: 3.2.0, built with Qt 5.12.4."

https://codereview.qt-project.org/c/qt/qtbase/+/272837 Fix QRandomGenerator initialization on AMD CPUs 

fixed it for 5.13 and a there we can see a cherry pick for 5.12:
https://codereview.qt-project.org/c/qt/qtbase/+/275914
which went in on 9th of October 2019.

Qt 5.12.4 was released on 17th of June 2019.
Qt 5.12.6 was released on 13th of November 2019, and should have the fix.

Installer needs to use an more up to date Qt.

Cheers,
Cristian.