Qt 5 to-do's in QString

qtbase/src/corelib/tools/qstring.h contains the following Qt 5 to-do comments:

    QString(const QChar *unicode, int size); // Qt5: don't cap size < 0
    explicit QString(const QChar *unicode); // Qt5: merge with the above

As this can be done without btreaking source-compatibility (by defaulting the second parameter of the first constructor), this is still a candidate for Qt 5.0.0.

These comments should be dealt with by actioning them, removing them, or changing them to Qt 6 to-do's.