The documentation used to have "Main Classes" list for C++ classes,
and qdoc kept track which classes were supposed to be listed as "main"
classes. This is no longer used, so this change removes the code that
marked a C++ class as a main class and tested whether a class was a
main class. This dead code was seen while preparing the way for
changing qdoc to output a documentation page for obsolete C++ classes
and functions and obsolete QML types and functions.
Task-number: QTBUG-30511
Change-Id: Iccc31b46b7c3c144038372cad4771d974f207937
Reviewed-by: Topi Reiniö <topi.reinio@digia.com>
Reviewed-by: Laszlo Papp <lpapp@kde.org>
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
7a66f6b60e