Add asn1c_helpers.c file to get type/enum/choice names for printing

Change-Id: I478d09776e58c86b84e82251f46f8d778b79a04c
diff --git a/src/asn1c_helpers.h b/src/asn1c_helpers.h
new file mode 100644
index 0000000..8d4e676
--- /dev/null
+++ b/src/asn1c_helpers.h
@@ -0,0 +1,7 @@
+#pragma once
+
+struct asn_TYPE_descriptor_t;
+
+const char *asn_type_name(const asn_TYPE_descriptor_t *td);
+const char *asn_choice_name(const asn_TYPE_descriptor_t *td, const void *sptr);
+const char *asn_enum_name(const asn_TYPE_descriptor_t *td, int data);