AK+LibGUI+LibWeb: Remove AK::TypeTraits in favor of RTTI-based helpers

Now that we have RTTI in userspace, we can do away with all this manual
hackery and use dynamic_cast.

We keep the is<T> and downcast<T> helpers since they still provide good
readability improvements. Note that unlike dynamic_cast<T>, downcast<T>
does not fail in a recoverable way, but will assert if the object being
casted is not a T.

Libraries/LibWeb/DOM/CharacterData.h

@@ -55,7 +55,3 @@ private:
 };
 
 }
-
-AK_BEGIN_TYPE_TRAITS(Web::DOM::CharacterData)
-static bool is_type(const Web::DOM::Node& node) { return node.is_character_data(); }
-AK_END_TYPE_TRAITS()

Libraries/LibWeb/DOM/Comment.h

@@ -42,7 +42,3 @@ public:
 };
 
 }
-
-AK_BEGIN_TYPE_TRAITS(Web::DOM::Comment)
-static bool is_type(const Web::DOM::Node& node) { return node.is_comment(); }
-AK_END_TYPE_TRAITS()

Libraries/LibWeb/DOM/Document.h

@@ -291,7 +291,3 @@ private:
 };
 
 }
-
-AK_BEGIN_TYPE_TRAITS(Web::DOM::Document)
-static bool is_type(const Web::DOM::Node& node) { return node.is_document(); }
-AK_END_TYPE_TRAITS()

Libraries/LibWeb/DOM/DocumentFragment.h

@@ -54,7 +54,3 @@ private:
 };
 
 }
-
-AK_BEGIN_TYPE_TRAITS(Web::DOM::DocumentFragment)
-static bool is_type(const Web::DOM::Node& node) { return node.is_document_fragment(); }
-AK_END_TYPE_TRAITS()

Libraries/LibWeb/DOM/DocumentType.h

@@ -56,7 +56,3 @@ private:
 };
 
 }
-
-AK_BEGIN_TYPE_TRAITS(Web::DOM::DocumentType)
-static bool is_type(const Web::DOM::Node& node) { return node.type() == Web::DOM::NodeType::DOCUMENT_TYPE_NODE; }
-AK_END_TYPE_TRAITS()

Libraries/LibWeb/DOM/Element.h

@@ -116,7 +116,3 @@ private:
 };
 
 }
-
-AK_BEGIN_TYPE_TRAITS(Web::DOM::Element)
-static bool is_type(const Web::DOM::Node& node) { return node.is_element(); }
-AK_END_TYPE_TRAITS()

Libraries/LibWeb/DOM/Node.h

@@ -162,7 +162,3 @@ protected:
 };
 
 }
-
-AK_BEGIN_TYPE_TRAITS(Web::DOM::Node)
-static bool is_type(const Web::DOM::EventTarget& event_target) { return event_target.is_node(); }
-AK_END_TYPE_TRAITS()

Libraries/LibWeb/DOM/ParentNode.h

@@ -66,7 +66,3 @@ inline void ParentNode::for_each_child(Callback callback)
 }
 
 }
-
-AK_BEGIN_TYPE_TRAITS(Web::DOM::ParentNode)
-static bool is_type(const Web::DOM::Node& node) { return node.is_parent_node(); }
-AK_END_TYPE_TRAITS()

Libraries/LibWeb/DOM/ShadowRoot.h

@@ -59,7 +59,3 @@ private:
 };
 
 }
-
-AK_BEGIN_TYPE_TRAITS(Web::DOM::ShadowRoot)
-static bool is_type(const Web::DOM::Node& node) { return node.is_shadow_root(); }
-AK_END_TYPE_TRAITS()

Libraries/LibWeb/DOM/Text.h

@@ -46,7 +46,3 @@ private:
 };
 
 }
-
-AK_BEGIN_TYPE_TRAITS(Web::DOM::Text)
-static bool is_type(const Web::DOM::Node& node) { return node.is_text(); }
-AK_END_TYPE_TRAITS()

Libraries/LibWeb/DOM/Window.h

@@ -98,7 +98,3 @@ private:
 };
 
 }
-
-AK_BEGIN_TYPE_TRAITS(Web::DOM::Window)
-static bool is_type(const Web::DOM::EventTarget& event_target) { return event_target.is_window(); }
-AK_END_TYPE_TRAITS()