[REG] C++ Debugger is *really* slow with QML Debugging enabled

I think that debugging QtCreator from within QtCreator is much slower than in previous versions.

Stepping over a line takes several seconds, rebuilding the locals over 10 seconds.

Sometimes even GDB runs in a timeout.

After I disabled the QML and Python Debugger, it is blazing fast again.

Unfortunately, I currently cannot reproduce it after enabling the QML and Python debuggers again and therefore I don't have a log.