RNA Types were storing an instance of themself for class introspection and docs but makes freeing the type complicated.

now __rna__ is a PyCObject rather then a BPy_StructRNA instance, to get the rna from python use __get_rna() now.

source/blender/python/epy_doc_gen.py

@@ -313,9 +313,9 @@ def rna2epy(target_path):
 	structs = []
 	for rna_type_name in dir(bpy.types):
 		rna_type = getattr(bpy.types, rna_type_name)
-		if hasattr(rna_type, '__rna__'):
+		if hasattr(rna_type, '__get_rna'):
 			#if not rna_type_name.startswith('__'):
-			rna_struct = rna_type.__rna__
+			rna_struct = rna_type.__get_rna()
 			identifier = rna_struct.identifier
 			structs.append( (base_id(rna_struct), identifier, rna_struct) )