Move type operations to another structure

Every type has free, print, check_constraints, ber_decoder, der_encoder,
xer_decoder, xer_encoder, uper_decoder, uper_encoder and outmost_tag
operations. We move them out to a separate structure asn_TYPE_operation_t.

Combined with previous logic simplification, these operations are based
on ASN.1 basic types, constructed types and string types. So we can
reduce the space occupied by asn_TYPE_descriptor_t variables.
diff --git a/skeletons/REAL.h b/skeletons/REAL.h
index 227c4b4..8bc0623 100644
--- a/skeletons/REAL.h
+++ b/skeletons/REAL.h
@@ -15,6 +15,7 @@
 typedef ASN__PRIMITIVE_TYPE_t REAL_t;
 
 extern asn_TYPE_descriptor_t asn_DEF_REAL;
+extern asn_TYPE_operation_t asn_OP_REAL;
 
 asn_struct_print_f REAL_print;
 asn_struct_compare_f REAL_compare;