Fix the following QDoc warnings:
* warning: Can't link to 'QRhiWidget::sampleConut'
* warning: Can't link to '`Q_NODISCARD_CTOR'
* warning: Invalid '\relates' (already a member of 'QEventLoopLocker')
* warning: Unknown command '\relatesalso'
* warning: Undocumented parameter 'separator' in QLocale::name()
* warning: clang couldn't find function when parsing \fn void QRhiWidget::framePresented()
In QAtomicPointer, work around the issue of QDoc not supporting
multiple \relates command for a single topic by adding a see-also
link to the global qYieldCpu() function.
Document the qvariant_cast() overload taking an rvalue reference.
Change-Id: I2528eee666149a97a14be059bbed537636d7aa0d
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
c46551e203