uint64_t and quint64 are treated differently in QML

I have provided a small example project in attachments.

When a Q_INVOKABLE returns uint64_t the value is implicitly converted to true for bool properties (and in signal handlers). Here is the log from the test project on my machine:
```
qml: uint64_t: Bool Property value: true
qml: uint64_t: Local var value: 0
qml: uint64_t: Local var bool cast: true
qml: quint64: Bool Property value: false
qml: quint64: Local var value: 0
qml: quint64: Local var cast: false
```
Both cases get a 0, they only differ in the return type. Seems like uint64_t is not converted correctly.