Clang code model underlines valid code

1. Enable the clang code model.
2. In a source file, include QDebug:

   #include <QDebug>
   

3. In some function in that file, add the line:

   qDebug() << "Failed";
   

   It will become underlined although the code is valid and can be compiled. Hovering it shows the tooltip:
   

4. Close and reopen the file.
   The underlines are gone.
5. Edit something in the file.
   The underlines are back.

The code model should not underline valid code. If it finds a real problem, the underline should not be gone after reopening a file.

Creator's built-in code model does not complain about this line.