Amends 55fe46fd58. Before that change,
key release events were ignored as the QLineEdit::event reimplementation
continued to call QWidget::event, and as QLineEdit didn't override
keyReleaseEvent, the default implementation in QWidget got called to
ignore the event.
Restore that behavior by explicitly calling the QWidget implementation
after updating QLineEdit-specific states, and add a test case.
Fixes: QTBUG-114654
Pick-to: 6.5 6.6
Change-Id: Ic8aa35a1c915b446aece47aaf03ef5cf1884b936
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>
8afe4faf29