REG: 5.15.0->5.15.1: Under some circumstances the performance of an application on Windows when switching application focus

REG: 5.15.0->5.15.1: Under some circumstances the performance of an application on Windows when switching application focus. This is due to the change 433d1b7efc0118f7d2d34803cdbd654d86c3aaf9 as commenting out the line QWindowsUiaMainProvider::notifyNameChange(event); in response to the NameChanged update in QWindowsUiaAccessibility::notifyAccessibilityUpdate(). This is not happening under all setups, and accessibility does not need to be enabled exactly to reproduce it. So something seems to be taking a lot of time as a result of the name change notification.