Disable threaded rendering for Intel HD 3000 cards.

Task-number: QTBUG-34492
Change-Id: I1848cde3fb9517679fd54a7170ed5bee40880edc
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
QIntegerForSize: add test

Make sure that the size of QIntegerForSize<N>::{Signed,Unsigned} is
actually N.

Change-Id: I221304f7c420e80758ef7b115bafb7cf1f8c8829
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>