[mutter] (5 commits) Non-fast-forward update to branch wip/muktupavels/work-areas-v2

[Alberts Muktupāvels <muktupavels src gnome org>]

The branch 'wip/muktupavels/work-areas-v2' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  b9ea391... x11-display: add support for _GTK_WORKAREAS_Dn

Commits added to the branch:

  7dbb4bc... window-actor/x11: Cache the client area (*)
  c0321c7... frame: Pass the frame area for get_mask() (*)
  1000ebe... window/x11: Add function to convert the buffer to frame rec (*)
  1ce933e... window-actor/x11: Get frame rect from the buffer size (*)
  5e07478... x11-display: add support for _GTK_WORKAREAS_Dn

(*) This commit already existed in another branch; no separate mail sent