Merge remote-tracking branch 'remotes/riku/tags/pull-linux-user-20171018' into staging

Merge remote-tracking branch 'remotes/riku/tags/pull-linux-user-20171018' into staging

Linux-user updates for Qemu 2.11

# gpg: Signature made Wed 18 Oct 2017 13:20:14 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-20171018:
  linux-user: Fix TARGET_MTIOCTOP/MTIOCGET/MTIOCPOS values
  linux-user/main: support dfilter
  linux-user: Fix target FS_IOC_GETFLAGS and FS_IOC_SETFLAGS numbers
  linux-user/sh4: Reduce TARGET_VIRT_ADDR_SPACE_BITS to 31
  linux-user: Tidy and enforce reserved_va initialization
  tcg: Fix off-by-one in assert in page_set_flags
  linux-user: Allow -R values up to 0xffff0000 for 32-bit ARM guests
  linux-user: remove duplicate break in syscall
  target/m68k,linux-user: manage FP registers in ucontext
  linux-user: fix O_TMPFILE handling

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