LibWeb: Implement named and indexed property access for HTMLFormElement

Author: https://github.com/ADKaster
Commit: b5ec520f84
Pull-request: https://github.com/SerenityOS/serenity/pull/22675
Reviewed-by: https://github.com/shannonbooth ✅

Userland/Libraries/LibWeb/HTML/HTMLFormElement.idl

@@ -2,7 +2,7 @@
 #import <HTML/HTMLElement.idl>
 
 // https://html.spec.whatwg.org/multipage/semantics.html#htmlformelement
-[Exposed=Window]
+[Exposed=Window, LegacyOverrideBuiltIns, LegacyUnenumerableNamedProperties]
 interface HTMLFormElement : HTMLElement {
 
     [HTMLConstructor] constructor();
@@ -21,8 +21,8 @@ interface HTMLFormElement : HTMLElement {
 
     [SameObject] readonly attribute HTMLFormControlsCollection elements;
     readonly attribute unsigned long length;
-    // FIXME: getter Element (unsigned long index);
-    // FIXME: getter (RadioNodeList or Element) (DOMString name);
+    getter Element (unsigned long index);
+    getter (RadioNodeList or Element) (DOMString name);
 
     undefined submit();
     // FIXME: undefined requestSubmit(optional HTMLElement? submitter = null);