feature/noverlay updated (246acbddbe -> 12836db6e4)

[Stefan Monnier]

monnier pushed a change to branch feature/noverlay.

      from  246acbddbe ; * test/src/buffer-tests.el: Remove unecessary 
`message' calls.
       new  67b9e89a5a Improve check_subtree
       new  51a8e375eb Check red-black invariants in most places
       new  a154259bfa Simplify itree_null initialization
       new  da0387f0fe Stop reading and writing the itree_null.parent field 
entirely.
       new  12836db6e4 itree.c (check_tree): Simplify


Summary of changes:
 src/itree.c | 184 +++++++++++++++++++++++++++++++++++++++---------------------
 1 file changed, 119 insertions(+), 65 deletions(-)