Merge branch 'ps/ref-consistency-checks' into jch

Update code paths that check data integrity around refs subsystem.

* ps/ref-consistency-checks:
  builtin/fsck: drop `fsck_head_link()`
  builtin/fsck: move generic HEAD check into `refs_fsck()`
  builtin/fsck: move generic object ID checks into `refs_fsck()`
  refs/reftable: introduce generic checks for refs
  refs/reftable: fix consistency checks with worktrees
  refs/reftable: extract function to retrieve backend for worktree
  refs/reftable: adapt includes to become consistent
  refs/files: introduce function to perform normal ref checks
  refs/files: extract generic symref target checks
  fsck: drop unused fields from `struct fsck_ref_report`
  refs/files: perform consistency checks for root refs
  refs/files: improve error handling when verifying symrefs
  refs/files: extract function to check single ref
  refs/files: remove useless indirection
  refs/files: remove `refs_check_dir` parameter
  refs/files: move fsck functions into global scope
  refs/files: simplify iterating through root refs

diff --cc builtin/fsck.c
index f671288026b4ef6073ea796368c9456ee9d7fcdc,f104b7af0e15f3a42cc4c3cd8fa5893c39ec9d97..0512f78a87fe1da9ceb8786da89d94a3e17df72e
--- 1/builtin/fsck.c
--- 2/builtin/fsck.c
+++ b/builtin/fsck.c
@@@ -596,11 -564,7 +596,7 @@@ static int fsck_handle_ref(const struc
        return 0;
  }
  
- static int fsck_head_link(const char *head_ref_name,
-                         const char **head_points_at,
-                         struct object_id *head_oid);
- 
 -static void get_default_heads(void)
 +static void snapshot_refs(struct snapshot *snap, int argc, const char **argv)
  {
        struct worktree **worktrees, **p;
        const char *head_points_at;

diff --cc refs.c
Simple merge