Merge remote-tracking branch 'remotes/riku/tags/pull-linux-user-20160921' into staging

Merge remote-tracking branch 'remotes/riku/tags/pull-linux-user-20160921' into staging

Linux-user changes, mostly bugfixes and adding support for some
new syscalls and some obscure syscalls as well. Includes some
missed patches from earlier rounds, and dropping unicore32 target.

v2: fix the syslog patch and test build with clang-3.8
v3: drop ustat patch

# gpg: Signature made Fri 21 Oct 2016 13:38:06 BST
# gpg:                using RSA key 0xB44890DEDE3C9BC0
# gpg: Good signature from "Riku Voipio <riku.voipio@iki.fi>"
# gpg:                 aka "Riku Voipio <riku.voipio@linaro.org>"
# Primary key fingerprint: FF82 03C8 C391 98AE 0581  41EF B448 90DE DE3C 9BC0

* remotes/riku/tags/pull-linux-user-20160921: (21 commits)
  linux-user: disable unicore32 linux-user build
  linux-user: added support for pwritev() system call.
  linux-user: added support for preadv() system call.
  linux-user: Fix fadvise64() syscall support for Mips32
  linux-user: Redirect termbits.h for Mips64 to termbits.h for Mips32
  linux-user: Update ioctls definitions for Mips32
  linux-user: Update mips_syscall_args[] array in main.c
  linux-user: Add support for syncfs() syscall
  linux-user: Add support for clock_adjtime() syscall
  linux-user: Fix definition of target_sigevent for 32-bit guests
  linux-user: use libc wrapper instead of direct mremap syscall
  linux-user: Don't use alloca() for epoll_wait's epoll event array
  linux-user: add RTA_PRIORITY in netlink
  linux-user: add kcmp() syscall
  linux-user: sparc64: Use correct target SHMLBA in shmat()
  linux-user: Remove a duplicate item from strace.list
  linux-user: Fix syslog() syscall support
  linux-user: Fix socketcall() syscall support
  linux-user: Fix msgrcv() and msgsnd() syscalls support
  linux-user: Fix mq_open() syscall support
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>