Merge remote-tracking branch 'remotes/qmp-unstable/queue/qmp' into staging

* remotes/qmp-unstable/queue/qmp: (32 commits)
  qapi: Add missing null check to opts_start_struct()
  qapi: Clean up superfluous null check in qapi_dealloc_type_str()
  qapi: Clean up null checking in generated visitors
  qapi: Drop unused code in qapi-commands.py
  qapi: Drop nonsensical header guard in generated qapi-visit.c
  qapi: Fix licensing of scripts
  tests/qapi-schema: Cover flat union types
  tests/qapi-schema: Cover union types with base
  tests/qapi-schema: Cover complex types with base
  tests/qapi-schema: Cover anonymous union types
  tests/qapi-schema: Cover simple argument types
  tests/qapi-schema: Cover optional command arguments
  tests/qapi-schema: Actually check successful QMP command response
  monitor: Remove left-over code in do_info_profile.
  qerror: Improve QERR_DEVICE_NOT_ACTIVE message
  qmp: Check for returned data from __json_read in get_events
  dump: add 'query-dump-guest-memory-capability' command
  Define the architecture for compressed dump format
  dump: make kdump-compressed format available for 'dump-guest-memory'
  dump: add API to write dump pages
  ...

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

diff --cc qapi-schema.json
Simple merge

diff --cc target-i386/cpu.h
Simple merge

diff --cc target-s390x/cpu.h
Simple merge