tests: add a test for pread/pwrite and preadv/pwritev offset decoding

* tests/uio.c: New file.
* tests/uio.test: New test.
* tests/Makefile.am (check_PROGRAMS): Add uio.
(uio_CFLAGS): Define.
(TESTS): Add uio.test.
Fix preadv/pwritev offset decoding

* util.c (printllval): Add align argument.
* defs.h (printllval): Update prototype.
(printllval_aligned, printllval_unaligned): New macros.
* file.c (sys_readahead, sys_truncate64, sys_ftruncate64, sys_fadvise64,
sys_fadvise64_64, sys_sync_file_range, sys_sync_file_range2,
sys_fallocate): Replace printllval call with printllval_aligned.
* io.c (sys_pread, sys_pwrite): Likewise.
(sys_preadv, sys_pwritev): Replace printllval call with
printllval_unaligned.
* linux/arm/syscallent.h: Set the number of preadv and pwritev
arguments to 5.
* linux/mips/syscallent-o32.h: Likewise.
* linux/powerpc/syscallent.h: Likewise.
* linux/sh/syscallent.h: Likewise.
* linux/xtensa/syscallent.h: Likewise.

Reported-by: Dima Kogan <dima@secretsauce.net>
Update CLOCK_* constants

* time.c (clocknames): Add CLOCK_BOOTTIME, CLOCK_REALTIME_ALARM,
CLOCK_BOOTTIME_ALARM, CLOCK_SGI_CYCLE, and CLOCK_TAI.
Fixes RH#1088455.
epoll_ctl: fix EPOLL_CTL_DEL argument decoding

* desc.c (sys_epoll_ctl): Do not parse the event structure for
EPOLL_CTL_DEL operation.

Reported-by: Марк Коренберг <socketpair@gmail.com>