2.2 migration note for %NativeFunctionPrototype%

doc/release-notes-v2-2.rst

@@ -19,3 +19,12 @@ from Duktape v2.1.x.  Note the following:
   longer a resized monolithic allocation which improves memory behavior for
   very low memory targets.  If you're using a pool allocator, you may need to
   measure and adjust pool sizes/counts.
+
+* Functions pushed using duk_push_c_function() and duk_push_c_lightfunc() now
+  inherit from an intermediate prototype (func -> %NativeFunctionPrototype%
+  -> Function.prototype) which provides ``.name`` and ``.length`` getters.
+  The setters are intentionally missing so direct writes for these properties
+  fail, but you can write them using ``Object.defineProperty()`` or
+  ``duk_def_prop()``.  The inherited getters can also be replaced if necessary.
+  The intermediate prototype doesn't have a named global binding, but you can
+  access it by reading the prototype of a pushed function.