Merge remote-tracking branch 'remotes/vivier2/tags/linux-user-for-4.0-pull-request...

- Update netlink types to linux v5.0
- fix accept4/getpeername/getsockname/recvfrom/recvmsg/read
- add/fix ELF_PLATFORM ofr aarch64 and arm
- fix "may be used uninitialized" warnings
- Fix breakpoint support in Nios
- Nicer strace output of chroot() syscall

# gpg: Signature made Thu 07 Mar 2019 10:06:16 GMT
# gpg:                using RSA key F30C38BD3F2FBE3C
# gpg: Good signature from "Laurent Vivier <lvivier@redhat.com>" [full]
# gpg:                 aka "Laurent Vivier <laurent@vivier.eu>" [full]
# gpg:                 aka "Laurent Vivier (Red Hat) <lvivier@redhat.com>" [full]
# Primary key fingerprint: CD2F 75DD C8E3 A4DC 2E4F  5173 F30C 38BD 3F2F BE3C

* remotes/vivier2/tags/linux-user-for-4.0-pull-request:
  linux-user: add new netlink types
  linux-user: Nicer strace output of chroot() syscall
  linux-user: fix "may be used uninitialized" warnings
  linux-user: don't short-circuit read with zero length
  Fix breakpoint support in Nios II user-mode emulation.
  linux-user: fix emulation of accept4/getpeername/getsockname/recvfrom syscalls
  linux-user: Fix ELF_PLATFORM for aarch64_be-linux-user
  linux-user: Add ELF_PLATFORM for arm
  linux-user: fix recvmsg emulation

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