The QHoverEvent ctor takes two points: pos and globalPos; pos is then
passed as both the scene and global pos to the QSinglePointEvent ctor,
which calls QMutableEventPoint::setScenePosition() on the persistent
QEventPoint instance and then detaches befeore setting ephemeral state.
Therefore, we must construct QHoverEvent with scene position first, not
local position, so that the right value is persisted; it's better to set
local position after the detach(), whereas it's too late to fix the
persistent point then.
Pick-to: 6.4
Fixes: QTBUG-106918
Change-Id: I45726a9ec05bba2fe0cde6f5fb87c269105caca6
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>