Fixed "cyclic" handling of generic extends.

decl.bmx

@@ -2649,7 +2649,9 @@ End Rem
 		'Semant superclass		
 		If superTy
 			'superClass=superTy.FindClass()
+			attrs :| DECL_CYCLIC
 			superClass=superTy.SemantClass()
+			attrs :~ DECL_CYCLIC
 			If superClass.IsInterface() Then
 				If Not IsExtern() Or Not superClass.IsExtern() Err superClass.ToString()+" is an interface, not a class."
 				If (IsExtern() And Not superClass.IsExtern()) Or (superClass.IsExtern() And Not IsExtern()) Err "Extern and non extern types cannot be mixed."