Merge remote-tracking branch 'remotes/bonzini-gitlab/tags/for-upstream' into staging

* configure and meson cleanups
* KVM_GET/SET_SREGS2 support for x86

# gpg: Signature made Wed 12 Jan 2022 13:09:19 GMT
# gpg:                using RSA key F13338574B662389866C7682BFFBD25F78C7AE83
# gpg:                issuer "pbonzini@redhat.com"
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full]
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>" [full]
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4  E2F7 7E15 100C CD36 69B1
#      Subkey fingerprint: F133 3857 4B66 2389 866C  7682 BFFB D25F 78C7 AE83

* remotes/bonzini-gitlab/tags/for-upstream:
  meson: reenable filemonitor-inotify compilation
  meson: build all modules by default
  configure: do not create roms/seabios/config.mak if SeaBIOS not present
  tests/tcg: Fix target-specific Makefile variables path for user-mode
  KVM: x86: ignore interrupt_bitmap field of KVM_GET/SET_SREGS
  KVM: use KVM_{GET|SET}_SREGS2 when supported.
  meson: add comments in the target-specific flags section
  configure, meson: move config-poison.h to meson
  meson: build contrib/ executables after generated headers
  configure: move non-command-line variables away from command-line parsing section
  configure: parse --enable/--disable-strip automatically, flip default
  configure, makefile: remove traces of really old files
  configure: do not set bsd_user/linux_user early
  configure: simplify creation of plugin symbol list
  block/file-posix: Simplify the XFS_IOC_DIOINFO handling
  meson: cleanup common-user/ build
  user: move common-user includes to a subdirectory of {bsd,linux}-user/
  meson: reuse common_user_inc when building files specific to user-mode emulators

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