Programs that read the members of archive (.a) files include <ar.h>
for struct ar_hdr and the ARMAG, SARMAG and ARFMAG constants, and
NuttX did not have it. The header describes the common ar file
format: the magic string, then a 60-byte ASCII header per member.
Assisted-by: Claude Code:claude-opus-5-5
Signed-off-by: Marco Casaroli <marco.casaroli@gmail.com>
