Annotations/@hide consistent across defined types.

@hide was missing for enum.

Probably, we should have something like 'AidlCommentable' to unify
duplicated logic surrounding having comments (and whether they are
hidden).

Bug: N/A
Test: N/A
Change-Id: I85c1976e5781f86c99cac610ab4e7b0950d46279
diff --git a/aidl_language.h b/aidl_language.h
index ada8832..bff983f 100644
--- a/aidl_language.h
+++ b/aidl_language.h
@@ -691,6 +691,7 @@
   }
 
   virtual void Dump(CodeWriter* writer) const = 0;
+  void DumpHeader(CodeWriter* writer) const;
 
  private:
   std::string name_;