aio: assorted iocb decoder updates

aio: assorted iocb decoder updates

* xlat/aio_iocb_flags.in: New file.
* defs.h (pollflags, rwf_flags): New declarations.
* configure.ac (AC_CHECK_MEMBERS): Check for aio_flags and aio_rw_flags
fields of struct iocb.
* aio.c [HAVE_STRUCT_IOCB_AIO_FLAGS]: Include "xlat/aio_iocb_flags.h".
(AIO_RW_FLAGS_FIELD): New macro definition, defined based on the
presence of HAVE_STRUCT_IOCB_AIO_RW_FLAGS macro.
(iocb_sub): Add SUB_POLL.
(tprint_lio_opcode): Change IOCB_CMD_POLL subtype to SUB_POLL.
(print_common_flags): Conditionalize on HAVE_STRUCT_IOCB_AIO_FLAGS
instead of IOCB_FLAG_RESFD.  Print aio_flags using aio_iocb_flags xlat.
(print_iocb_header): Always print aio_data.  Print aio_rw_flags if it
is non-zero.  Print aio_reqprio based on the presence of
IOCB_FLAG_IOPRIO flag in aio_flags (use print_ioprio if it set and print
as a signed integer otherwise).
(print_iocb): Decode SUB_POLL subtype.
* tests/aio.c: Update expected output.

Co-Authored-by: Dmitry V. Levin <ldv@altlinux.org>