The macro Q_DECLARE_INTERFACE declared some qobject_cast() functions
that clang-qdoc must not see in the contexts where the macro is used.
This update prevents that from happening by ensuring that Q_CLANG_QDOC
is not defined when the macro is defined.
This update also adds a \fn command for a declaration of qobject_cast()
that was missing in the documentation. There are two versions of the
function, one with a const parameter and one with a non-const parameter,
and they both share one qdoc comment.
Change-Id: Ic74d0aaae62767cd0391474ee95ae3f4f820b06e
Reviewed-by: Topi Reiniö <topi.reinio@qt.io>
4ca0d76454