QmlJSEditor: Expose helper function for auto completion

The function qmlJSAutoComplete() will be used by the QmlDesigner.

Change-Id: If569e3f22e2dd934b9043b2e139da597686496ae
Reviewed-by: Marco Benelli <marco.benelli@qt.io>

src/plugins/qmljseditor/qmljscompletionassist.h

@@ -134,4 +134,10 @@ private:
     QIcon m_darkCyanIcon;
 };
 
+QStringList QMLJSEDITOR_EXPORT qmlJSAutoComplete(QTextDocument *textDocument,
+                                                 int position,
+                                                 const QString &fileName,
+                                                 TextEditor::AssistReason reason,
+                                                 const QmlJSTools::SemanticInfo &info);
+
 } // QmlJSEditor