LibWeb: Define SVGImageElement destructor for Core::Timer forward decl

This fixes a "error: member access into incomplete type 'Core::Timer'"
build error on clang-cl Windows.

Author: ayeteadoe

Libraries/LibWeb/SVG/SVGImageElement.cpp

@@ -27,6 +27,8 @@ SVGImageElement::SVGImageElement(DOM::Document& document, DOM::QualifiedName qua
     m_animation_timer->on_timeout = [this] { animate(); };
 }
 
+SVGImageElement::~SVGImageElement() = default;
+
 void SVGImageElement::initialize(JS::Realm& realm)
 {
     WEB_SET_PROTOTYPE_FOR_INTERFACE(SVGImageElement);

Libraries/LibWeb/SVG/SVGImageElement.h

@@ -20,6 +20,8 @@ class SVGImageElement final
     WEB_PLATFORM_OBJECT(SVGImageElement, SVGGraphicsElement);
 
 public:
+    ~SVGImageElement();
+
     virtual void attribute_changed(FlyString const& name, Optional<String> const& old_value, Optional<String> const& value, Optional<FlyString> const& namespace_) override;
 
     GC::Ref<SVG::SVGAnimatedLength> x();