As reported by John Fisher, the IDL below does not work. It looks like there is
a problem in src/org/jacorb/idl/NameTable.java relating to shadowed enums. I've
attached a patch that seems to fix the problem.

interface A {
   enum my_enum {
      ENUM1,
      ENUM2
   };
};

interface B : A {
   enum my_enum {
      ENUM1,
      ENUM3
   };
};