Functions are not automatically detected hence there's no e.g. prediction, highlight with Qt5.15 kits

Some functions are not automatically detected by Qt Creator hence there's no editing function such as showing candidates or highlighting.

• Happens with Qt Creator at least between v4.13 - v4.14.
• Happens with Qt5.15 series kit but not with Qt5.12 series
• Appears when Clang Code model is OFF

*How to reproduce *
Use 4000Chips Qt Sample (https://doc.qt.io/qt-5/qtwidgets-graphicsview-chip-example.html).
Select Qt5.15.x as the kit

See the attached screenshots as a reference.
The functions in the constructor such as setZValue or setFlags are not detected with Qt5.15.2 kit while they are with Qt5.12.9 kit.

Qt5.15.2

Qt5.12.9