C++: Update expected test results

Author: jketema

cpp/ql/test/library-tests/ir/ir/PrintConfig.qll

@@ -20,5 +20,7 @@ predicate shouldDumpDeclaration(Declaration decl) {
     decl.(GlobalOrNamespaceVariable).hasInitializer()
     or
     decl.(StaticLocalVariable).hasInitializer()
+    or
+    decl.(Field).hasInitializer()
   )
 }