C++11: Make 'enum struct', enum-base and opaque enum decls work.

For declarations like:
enum struct Foo : long int;

Change-Id: Id813efdbc31c8d70a4b40bb0101dc33a8dd2556a
Reviewed-by: hjk <qthjk@ovi.com>

src/libs/3rdparty/cplusplus/AST.h

@@ -1634,7 +1634,10 @@ class CPLUSPLUS_EXPORT EnumSpecifierAST: public SpecifierAST
 {
 public:
     unsigned enum_token;
+    unsigned key_token; // struct, class or 0
     NameAST *name;
+    unsigned colon_token; // can be 0 if there is no enum-base
+    SpecifierListAST *type_specifier_list; // ditto
     unsigned lbrace_token;
     EnumeratorListAST *enumerator_list;
     unsigned stray_comma_token;
@@ -1646,7 +1649,10 @@ public: // annotations
 public:
     EnumSpecifierAST()
         : enum_token(0)
+        , key_token(0)
         , name(0)
+        , colon_token(0)
+        , type_specifier_list(0)
         , lbrace_token(0)
         , enumerator_list(0)
         , stray_comma_token(0)