[Reg 5.11.0->5.11.1] Assert when hiding widget in destructor of parent (was: QC sometimes crashes on close)

Easiest way to reproduce:

• build QC with plugin unit tests and run QC with e.g. '-test Android' (it seems to need a plugin that has no unit tests defined)
• might be necessary to repeat this (starting QC over and over again)

Dialog comes up with

ASSERT failure in QWeakPointer: "Detected QWeakPointer creation in a QObject being deleted", file tools\qsharedpointer.cpp, line 1456

and I managed to attach to a crashed QC and got the back trace attached to this report