new syscall in linux commit 916cda1aa1b412d7cf2991c3af7479544942d121

statx was added in linux commit a528d35e8bfcc521d7cb70aaf03e1bd296c8493f
(there is no libc wrapper yet and microblaze and sh misses the number).

aligned with linux arch/s390/include/asm/elf.h
(these macros should be exported into uapi, but they are not)

it is defined in linux asm/sockios.h since commit
ae40eb1ef30ab4120bd3c8b7e3da99ee53d27a23 (linux v2.6.22)
but was missing from musl by accident.

in musl the sockios macros are exposed in sys/ioctl.h together
with other ioctl requests instead of in sys/socket.h because of
namespace rules. (glibc has them in sys/socket.h under _GNU_SOURCE.)

This structure was missed when creating the s390x port.

This is based on the report and patch from William Pitcock, but with a
modified structure defintion to more closely match the kernel's
definition.

Including sys/procfs.h complains unknown type name 'fpreg_t' in
bits/user.h. fpreg_t in bits/signal.h and elf_fpreg_t in bits/user.h
are practically the same.

per_struct is never used, even conflicts with kernel header
asm/ptrace.h