Merge remote-tracking branch 'remotes/marcandre/tags/for-6.0-pull-request' into staging

For 6.0 misc patches under my radar.

V2:
 - "tests: Add tests for yank with the chardev-change case" updated
 - drop the readthedoc theme patch

# gpg: Signature made Thu 01 Apr 2021 12:54:52 BST
# gpg:                using RSA key 87A9BD933F87C606D276F62DDAE8E10975969CE5
# gpg:                issuer "marcandre.lureau@redhat.com"
# gpg: Good signature from "Marc-André Lureau <marcandre.lureau@redhat.com>" [full]
# gpg:                 aka "Marc-André Lureau <marcandre.lureau@gmail.com>" [full]
# Primary key fingerprint: 87A9 BD93 3F87 C606 D276  F62D DAE8 E109 7596 9CE5

* remotes/marcandre/tags/for-6.0-pull-request:
  tests: Add tests for yank with the chardev-change case
  chardev: Fix yank with the chardev-change case
  chardev/char.c: Always pass id to chardev_new
  chardev/char.c: Move object_property_try_add_child out of chardev_new
  yank: Always link full yank code
  yank: Remove dependency on qiochannel
  docs: simplify each section title
  dbus-vmstate: Increase the size of input stream buffer used during load
  util: fix use-after-free in module_load_one

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

diff --cc docs/devel/index.rst
Simple merge

diff --cc migration/meson.build
Simple merge