QmlOutline: Show functions in outline

Reviewed-by: Christiaan Janssen
(cherry picked from commit e871b7e330)

src/libs/qmljs/qmljsicons.h

@@ -53,6 +53,7 @@ public:
     QIcon objectDefinitionIcon() const;
     QIcon scriptBindingIcon() const;
     QIcon publicMemberIcon() const;
+    QIcon functionDeclarationIcon() const;
 
 private:
     Icons();