[gegl] Non-fast-forward update to branch wip/rishi/buffer-set-abyss-bottom-negative

[Debarshi Ray <debarshir src gnome org>]

The branch 'wip/rishi/buffer-set-abyss-bottom-negative' 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:

  d5abd2b... buffer: Fix handling of the bottom abyss edge for negative 

Commits added to the branch:

  d21356c... buffer: Fix handling of the bottom abyss edge for negative