Merge remote-tracking branch 'remotes/huth-gitlab/tags/pull-request-2020-07-13' into staging

* Some fuzzer related fixes
* Fixes / improvements for the "configure" script
* Doc updates
* Gitlab pipeline-status script

# gpg: Signature made Mon 13 Jul 2020 11:48:32 BST
# gpg:                using RSA key 27B88847EEE0250118F3EAB92ED9D774FE702DB5
# gpg:                issuer "thuth@redhat.com"
# gpg: Good signature from "Thomas Huth <th.huth@gmx.de>" [full]
# gpg:                 aka "Thomas Huth <thuth@redhat.com>" [full]
# gpg:                 aka "Thomas Huth <huth@tuxfamily.org>" [full]
# gpg:                 aka "Thomas Huth <th.huth@posteo.de>" [unknown]
# Primary key fingerprint: 27B8 8847 EEE0 2501 18F3  EAB9 2ED9 D774 FE70 2DB5

* remotes/huth-gitlab/tags/pull-request-2020-07-13:
  docs/system/s390x: Improve the 3270 documentation
  GitLab Gating CI: introduce pipeline-status contrib script
  disas/sh4: Add missing fallthrough annotations
  Remove the CONFIG_PRAGMA_DIAGNOSTIC_AVAILABLE switch
  docs/devel/fuzzing: Fix bugs in documentation
  tests/qtest/fuzz: Add missing spaces in description
  fuzz: add missing header for rcu_enable_atfork
  configure: do not clobber CFLAGS with --enable-fuzzing
  configure: fix malloc check

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