Add type_dynamic_cast and friends for java_class_typet

Add type_dynamic_cast and friends for struct_typet, class_typet and java_class_typet

Author: NathanJPhillips

src/java_bytecode/java_types.h

@@ -146,6 +146,12 @@ inline java_class_typet &to_java_class_type(typet &type)
   return static_cast<java_class_typet &>(type);
 }
 
+template <>
+inline bool can_cast_type<java_class_typet>(const typet &type)
+{
+  return can_cast_type<class_typet>(type);
+}
+
 typet java_int_type();
 typet java_long_type();
 typet java_short_type();

src/util/std_types.h

@@ -328,6 +328,12 @@ inline struct_typet &to_struct_type(typet &type)
   return static_cast<struct_typet &>(type);
 }
 
+template <>
+inline bool can_cast_type<struct_typet>(const typet &type)
+{
+  return type.id() == ID_struct;
+}
+
 /*! \brief C++ class type
 */
 class class_typet:public struct_typet
@@ -432,6 +438,12 @@ inline class_typet &to_class_type(typet &type)
   return static_cast<class_typet &>(type);
 }
 
+template <>
+inline bool can_cast_type<class_typet>(const typet &type)
+{
+  return can_cast_type<struct_typet>(type) && type.get_bool(ID_C_class);
+}
+
 /*! \brief The union type
 */
 class union_typet:public struct_union_typet