AK: Really disallow making OwnPtrs from refcounted types

This looks at three things:
- if the type has a typedef `AllowOwnPtr', respect that
- if not, disallow construction if both of `ref()' and `unref()' are
  present.
Note that in the second case, if a type only defines `ref()' or only
defines `unref()', an OwnPtr can be created, as a RefPtr of that type
would be ill-formed.

Also marks a `Performance' to explicitly allow OwnPtrs.

Libraries/LibWeb/HighResolutionTime/Performance.h

@@ -26,6 +26,7 @@
 
 #pragma once
 
+#include <AK/StdLibExtras.h>
 #include <LibCore/ElapsedTimer.h>
 #include <LibWeb/Bindings/Wrappable.h>
 #include <LibWeb/DOM/EventTarget.h>
@@ -37,6 +38,7 @@ class Performance final
     , public Bindings::Wrappable {
 public:
     using WrapperType = Bindings::PerformanceWrapper;
+    using AllowOwnPtr = AK::TrueType;
 
     explicit Performance(DOM::Window&);
     ~Performance();