C++ front-end: not all declarators are code-typed

The example included as regression test has a bool instead.

Author: tautschnig

regression/cbmc-cpp/Templates31/test.desc

@@ -1,4 +1,4 @@
-KNOWNBUG
+CORE
 main.cpp
 
 ^EXIT=0$

regression/cpp/Templates3/main.cpp

@@ -0,0 +1,14 @@
+template <class _Tp, _Tp __v>
+struct integral_constant
+{
+  static const _Tp value = __v;
+};
+
+template <class _Tp, _Tp __v>
+const _Tp integral_constant<_Tp, __v>::value;
+
+typedef integral_constant<bool, true> true_type;
+
+int main(int argc, char *argv[])
+{
+}

regression/cpp/Templates3/test.desc

@@ -0,0 +1,8 @@
+CORE
+main.cpp
+
+^EXIT=0$
+^SIGNAL=0$
+--
+^warning: ignoring
+^CONVERSION ERROR$

src/cpp/cpp_declarator_converter.cpp

@@ -163,7 +163,9 @@ symbolt &cpp_declarator_convertert::convert(
 
     // If it is a constructor, we take care of the
     // object initialization
-    if(to_code_type(final_type).return_type().id() == ID_constructor)
+    if(
+      final_type.id() == ID_code &&
+      to_code_type(final_type).return_type().id() == ID_constructor)
     {
       const cpp_namet &name=declarator.name();