add '--enable-debug' configure option to build with EMIT_ASN_DEBUG
... which in turn causes all the ASN_DEBUG() to be turned into
fprintf(stderr, ...) statements, once the user application decides
to set 'asn_debug = 1' somewhere in its code.
The next step would be to make _ASN_DECODE_FAILED / _ASN_ENCODE_FAILED
no longer depend on ASN_DEBUG (which it currently does)
diff --git a/src/asn_codecs_prim.c b/src/asn_codecs_prim.c
index 8e604a4..53d20c0 100644
--- a/src/asn_codecs_prim.c
+++ b/src/asn_codecs_prim.c
@@ -6,6 +6,10 @@
#include <asn_codecs_prim.h>
#include <errno.h>
+#if EMIT_ASN_DEBUG == 1
+int asn_debug = 0;
+#endif
+
/*
* Decode an always-primitive type.
*/