various fixes to remove warnings

git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk/SWIG@6580 626c5289-ae23-0410-ae9c-e8d60b6d4f22

Examples/test-suite/enum_thorough.i

@@ -442,11 +442,9 @@ namespace curly {
 }
 
 struct Obscure {
-  enum {};
   enum Zero {};
   enum One {one};
   enum Two {two, twoagain};
-  typedef enum {};
   typedef enum Empty {};
   typedef enum {} AlsoEmpty;
 };