py_loxi: support/resolve enum members of structs
diff --git a/py_gen/templates/_pack.py b/py_gen/templates/_pack.py
index 9956cf6..0525ef2 100644
--- a/py_gen/templates/_pack.py
+++ b/py_gen/templates/_pack.py
@@ -37,19 +37,19 @@
 ::     if type(m) == OFLengthMember:
 ::         length_member = m
 ::         length_member_index = index
-        packed.append(${gen_pack_expr(m.oftype, '0')}) # placeholder for ${m.name} at index ${index}
+        packed.append(${gen_pack_expr(m.oftype, '0', version=version)}) # placeholder for ${m.name} at index ${index}
 ::     elif type(m) == OFFieldLengthMember:
 ::         field_length_members[m.field_name] = m
 ::         field_length_indexes[m.field_name] = index
-        packed.append(${gen_pack_expr(m.oftype, '0')}) # placeholder for ${m.name} at index ${index}
+        packed.append(${gen_pack_expr(m.oftype, '0', version=version)}) # placeholder for ${m.name} at index ${index}
 ::     elif type(m) == OFPadMember:
         packed.append('\x00' * ${m.length})
 ::     else:
-        packed.append(${gen_pack_expr(m.oftype, 'self.' + m.name)})
+        packed.append(${gen_pack_expr(m.oftype, 'self.' + m.name, version=version)})
 ::         if m.name in field_length_members:
 ::             field_length_member = field_length_members[m.name]
 ::             field_length_index = field_length_indexes[m.name]
-        packed[${field_length_index}] = ${gen_pack_expr(field_length_member.oftype, 'len(packed[-1])')}
+        packed[${field_length_index}] = ${gen_pack_expr(field_length_member.oftype, 'len(packed[-1])', version=version)}
 ::         #endif
 ::     #endif
 ::     index += 1
@@ -60,7 +60,7 @@
         packed.append(loxi.generic_util.pad_to(8, length))
         length += len(packed[-1])
 :: #endif
-        packed[${length_member_index}] = ${gen_pack_expr(length_member.oftype, 'length')}
+        packed[${length_member_index}] = ${gen_pack_expr(length_member.oftype, 'length', version=version)}
 :: #endif
 :: if ofclass.has_external_alignment:
         packed.append(loxi.generic_util.pad_to(8, length))