Merge remote-tracking branch 'remotes/vivier2/tags/linux-user-for-4.2-pull-request...

Merge remote-tracking branch 'remotes/vivier2/tags/linux-user-for-4.2-pull-request' into staging

sparc/sparc64 fixes: this doesn't fix debian chroot for me
but they are a step in the good direction.
Fix Netlink support.
Trivial fix for alpha

PULL v2: fix checkpatch warnings

# gpg: Signature made Wed 06 Nov 2019 13:04:36 GMT
# gpg:                using RSA key CD2F75DDC8E3A4DC2E4F5173F30C38BD3F2FBE3C
# gpg:                issuer "laurent@vivier.eu"
# 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-4.2-pull-request:
  linux-user/alpha: Set r20 secondary return value
  linux-user/sparc: Fix cpu_clone_regs_*
  linux-user: Introduce cpu_clone_regs_parent
  linux-user: Rename cpu_clone_regs to cpu_clone_regs_child
  linux-user/sparc64: Fix target_signal_frame
  linux-user/sparc: Fix WREG usage in setup_frame
  linux-user/sparc: Use WREG_SP constant in sparc/signal.c
  linux-user/sparc: Begin using WREG constants in sparc/signal.c
  linux-user/sparc: Use WREG constants in sparc/target_cpu.h
  target/sparc: Define an enumeration for accessing env->regwptr
  tests/tcg/multiarch/linux-test: Fix error check for shmat
  scripts/qemu-binfmt-conf: Update for sparc64
  linux-user: Support for NETLINK socket options

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