Decode file descriptors returned by accept and accept4 syscalls

* net.c (do_accept): Rename to do_sockname.
(sys_accept, sys_accept4): Update callers, return RVAL_FD.
(sys_getsockname, sys_getpeername): Call do_sockname directly.
* tests/net-fd.test: Update.
Fix preadv/pwritev offset decoding on bigendian architectures

This partially reverts commit 7845a42b39e59e904d01e75e21f7bc7eb6462560.

* util.c (printllval): Remove align argument.
* defs.h (printllval): Update prototype.
(printllval_aligned, printllval_unaligned): Remove.
* 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_aligned call with printllval.
* io.c (sys_pread, sys_pwrite): Likewise.
(print_llu_from_low_high_val): New function.
(sys_preadv, sys_pwritev): Use it instead of printllval_unaligned.
Fix preadv/pwritev offset decoding on ILP32 architectures

This fixes regression introduced by the previous commit.

* io.c (print_llu_from_low_high_val) [SIZEOF_LONG != SIZEOF_LONG_LONG]:
Cast argument to unsigned long before casting it to unsigned long long.
Prepare for -yy option support

* defs.h (show_fd_path): Change type to unsigned int.
* strace.c (show_fd_path): Likewise.
(init): Handle repeated -y option.
alpha: fix sigaction decoding

Since the rt_sigaction syscall on alpha doesn't have a sa_restorer,
do not include it in the kernel struct.

* signal.c (struct new_sigaction): Disable sa_restorer on alpha.
hppa: fix sigaction decoding

Since the rt_sigaction syscall on hppa doesn't have a sa_restorer,
do not include it in the kernel struct.

We also have to undefine SA_RESTORER so that code doesn't try to
use it.  The headers will export this, but the syscall doesn't
actually respect it.

* signal.c (SA_RESTORER): Undefine when HPPA is defined.
(struct new_sigaction): Disable sa_restorer on hppa.
alpha/sparc: fix arg count for rt_sigaction

Both these arches have a rt_sigaction syscall that takes 5 args, not 4.

* linux/alpha/syscallent.h (rt_sigaction): Change nargs to 5.
* linux/sparc/syscallent.h (rt_sigaction): Change nargs to 5.
sigaction test: support arches w/out SA_RESTORER and swapped args

Running Linux 3.15 (sparc64) and glibc 2.17 (sparc32) triggers a
rt_sigaction call that does not use SA_RESTORER and has an order
where it inserts a restorer and a size.  The current tests don't
support that ordering, so add another regex.

* tests/sigaction.awk: Support no SA_RESTORER and swapped args.
signal: fix thinko in sa_restorer

Previous commit here re-added the bugs trying to be fixed due to a
logic thinko.  The patches were tested in isolation and hand merged
later.  Oops.

* signal.c (struct new_sigaction): Change || to &&.