QFile::permissions reports wrong permissions in t 5.10

Initially found while investigating a test failure in the KDE messagelib repo.

QFile:permissions doesn't return the same flags if it uses statx.

#include <QFile>
#include <QDebug>
int main(int argc, char *argv[]) \{
  qDebug() << QFile(argv[1]).permissions();
}

touch test
chmod 777 test

./testPermissions test

With Qt 5.10 : QFlags(0x1|0x2|0x4|0x10|0x20|0x40|0x1000|0x2000|0x4000)
With Qt 5.9 : QFlags(0x1|0x2|0x4|0x10|0x20|0x40|0x100|0x200|0x400|0x1000|0x2000|0x4000)