Change the names of the node reference counting functions
and add comments to make the mechanism easier to understand:
- new_reference() and decrement_references() are now called
dns__rbtnode_acquire() and dns__rbtnode_release()
respectively; this reflects the fact that they modify both
the internal and external reference counters for a node.
- rbtnode_newref() and rbtnode_decref are now called
rbtnode_erefs_increment() and rbtnode_erefs_decrement(),
to reflect that they only increase and decrease the node's
external reference counters, not internal.
(cherry picked from commit 857225aeb6)
Ondřej Surý
2974bbba80