gpg: Extend free_packet to handle a packet parser context.
* g10/packet.h (struct parse_packet_ctx_s): Add fields LAST_PKT and FREE_LAST_PKT. (init_parse_packet): Clear them. (deinit_parse_packet): New macro. Change all users if init_parse_packet to also call this macro. * g10/free-packet.c (free_packet): Add arg PARSECTX and handle shallow packet copies in the context. Change all callers. * g10/parse-packet.c (parse): Store certain packets in the parse context.
- Signed-off-by: Werner Koch <wk@gnupg.org>