LibWeb/WebGL: Preserve original bound objects to return in getParameter

Required by https://qwasm2.m-h.org.uk, which adds a custom `name`
attribute to objects it generates. It then gets some of these objects
out with getParameter, and expects the `name` attribute to be there.

Libraries/LibWeb/WebGL/WebGLRenderingContext.cpp

@@ -86,6 +86,7 @@ void WebGLRenderingContext::initialize(JS::Realm& realm)
 void WebGLRenderingContext::visit_edges(Cell::Visitor& visitor)
 {
     Base::visit_edges(visitor);
+    WebGLRenderingContextImpl::visit_edges(visitor);
     visitor.visit(m_canvas_element);
 }