A bit hacky: the ranap_ies_defs.h is generated together with the
ranap_encoder.c and ranap_decoder.c. See comments in src/Makefile.am and
include/osmocom/ranap/Makefile.am.
encoding correctness still needs to be verified at this point. At least
they generate some binary output without failing somewhere earlier in
the encoding process - and they don't leave any leaked memory behind,
see talloc_report() at the end of test-ranap.c:main().