Make manual isSVG*Element() helpers as efficient as the generated ones

Source/core/svg/SVGTextPositioningElement.h

Index: Source/core/svg/SVGTextPositioningElement.h
diff --git a/Source/core/svg/SVGTextPositioningElement.h b/Source/core/svg/SVGTextPositioningElement.h
index bc6ea0ffb4d1df80b36806dc964c7f6f55289c4c..490579961474019940f01305d9080aafa312deac 100644
--- a/Source/core/svg/SVGTextPositioningElement.h
+++ b/Source/core/svg/SVGTextPositioningElement.h
@@ -53,12 +53,12 @@ protected:
     RefPtr<SVGAnimatedNumberList> m_rotate;
 };
 
-inline bool isSVGTextPositioningElement(const Node& node)
+inline bool isSVGTextPositioningElement(const SVGElement& element)
 {
-    return node.isSVGElement() && toSVGElement(node).isTextPositioning();
+    return element.isTextPositioning();
 }
 
-DEFINE_ELEMENT_TYPE_CASTS_WITH_FUNCTION(SVGTextPositioningElement);
+DEFINE_SVGELEMENT_TYPE_CASTS_WITH_FUNCTION(SVGTextPositioningElement);
 
 } // namespace blink