QDoc: Replace qmlElement with qmlNativeType in ClassNode

Since the introduction of the new '\nativetype' command and the
subsequent deprecation of the '\instantiates' command, the notion of a
"qml element" that belongs to a `ClassNode` is made redundant. The only
external use of the related API in `ClassNode` is in
`Tree::resolveCppToQmlLinks`. This change replaces the call to
`setQmlElement` with a call to `insertQmlNativeType`, which is the
corresponding setter for the new QDoc command. This ensures full
feature parity between the new and old commands, and leaves the
setter, getter, and data member in `ClassNode` unused, and therefore
removed.

Task-number: QTBUG-125368
Change-Id: If0b541844f27fe4455ad1ae27c82d471611e2e81
Reviewed-by: Topi Reiniö <topi.reinio@qt.io>

src/qdoc/qdoc/src/qdoc/classnode.h

@@ -41,8 +41,6 @@ public:
 
     [[nodiscard]] const QList<RelatedClass> &baseClasses() const { return m_bases; }
 
-    QmlTypeNode *qmlElement() { return m_qmlElement; }
-    void setQmlElement(QmlTypeNode *qcn) { m_qmlElement = qcn; }
     [[nodiscard]] bool isAbstract() const override { return m_abstract; }
     void setAbstract(bool b) override { m_abstract = b; }
     PropertyNode *findPropertyNode(const QString &name);
@@ -63,7 +61,6 @@ private:
     QList<RelatedClass> m_ignoredBases {};
     bool m_abstract { false };
     bool m_wrapper { false };
-    QmlTypeNode *m_qmlElement { nullptr };
     QSet<QmlTypeNode *> m_nativeTypeForQml;
 };
 

src/qdoc/qdoc/src/qdoc/tree.cpp

@@ -283,7 +283,7 @@ void Tree::resolveCppToQmlLinks()
             auto *qcn = static_cast<QmlTypeNode *>(child);
             auto *cn = const_cast<ClassNode *>(qcn->classNode());
             if (cn)
-                cn->setQmlElement(qcn);
+                cn->insertQmlNativeType(qcn);
         }
     }
 }