[mutter] (5 commits) Non-fast-forward update to branch wip/carlosg/dnd-crash-fix

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

The branch 'wip/carlosg/dnd-crash-fix' 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:

  4858500... wayland: Unset DnD selection on wl_data_offer destruction

Commits added to the branch:

  1b61b9c... boxes: Fix calculation of rounded rectangles (*)
  2145333... renderer/native: Refactor into secondary_gpu_get_next_dumb_ (*)
  a859d76... meson: Cleanup debug build handling (*)
  75e2bfb... meson: Do not add compiler flags if 'plain' buildtype is us (*)
  b3e19ee... wayland: Unset DnD selection on wl_data_offer destruction

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