Merge branch 'en/ort-readiness'

Plug the ort merge backend throughout the rest of the system, and
start testing it as a replacement for the recursive backend.

* en/ort-readiness:
  Add testing with merge-ort merge strategy
  t6423: mark remaining expected failure under merge-ort as such
  Revert "merge-ort: ignore the directory rename split conflict for now"
  merge-recursive: add a bunch of FIXME comments documenting known bugs
  merge-ort: write $GIT_DIR/AUTO_MERGE whenever we hit a conflict
  t: mark several submodule merging tests as fixed under merge-ort
  merge-ort: implement CE_SKIP_WORKTREE handling with conflicted entries
  t6428: new test for SKIP_WORKTREE handling and conflicts
  merge-ort: support subtree shifting
  merge-ort: let renormalization change modify/delete into clean delete
  merge-ort: have ll_merge() use a special attr_index for renormalization
  merge-ort: add a special minimal index just for renormalization
  merge-ort: use STABLE_QSORT instead of QSORT where required

diff --cc builtin/rebase.c
Simple merge

diff --cc ci/run-build-and-tests.sh
Simple merge

diff --cc merge-ort.c
index 028d712f5406ff4f17b3834d2c25f7c13118d848,8258d3fd621e0fe1c8602c3e43bb98f7ef4c5dd7..d1f4cf8a1f2ed404c697bcabf36ef63a072a0f7f
--- 1/merge-ort.c
--- 2/merge-ort.c
+++ b/merge-ort.c
@@@ -25,6 -26,6 +26,7 @@@
  #include "diff.h"
  #include "diffcore.h"
  #include "dir.h"
++#include "entry.h"
  #include "ll-merge.h"
  #include "object-store.h"
  #include "revision.h"

diff --cc merge-recursive.c
Simple merge

diff --cc sequencer.c
Simple merge

diff --cc t/t6423-merge-rename-directories.sh
Simple merge

diff --cc t/test-lib.sh
Simple merge