port/merge Eurecom APER support from OPENAIRMME

Eurecom has developed APER support for asn1c as part of the OPENAIRMME
softare (a LTE MME).  This is too important to let it bit-rout out
of asn1c.  Let's forward-port and merge it.
diff --git a/skeletons/constr_SET.h b/skeletons/constr_SET.h
index 6a3a1aa..11b7153 100644
--- a/skeletons/constr_SET.h
+++ b/skeletons/constr_SET.h
@@ -53,7 +53,9 @@
 xer_type_decoder_f SET_decode_xer;
 xer_type_encoder_f SET_encode_xer;
 per_type_decoder_f SET_decode_uper;
+per_type_decoder_f SET_decode_aper;
 per_type_encoder_f SET_encode_uper;
+per_type_encoder_f SET_encode_aper;
 
 /***********************
  * Some handy helpers. *