QUnifiedTimer stops updating animation timers after long period of time

-Start attached qml example
-Leave it running for ~5 days
-Animation stops

Using a debugger we see that delta in QUnifiedTimer::updateAnimationTimers is always 0, because QUnifiedTimer::elapsed() returns the same tick value on every call. Because delta is 0, none of the animation timers are updated.

If we break into the updateAnimationTimers using a debugger and continue executing again, elapsed() will return new values causing delta to become postive and animation resuming. The problem reappears when normal execution is resumed.