Merge branch 'en/header-split-cache-h-part-3'

Header files cleanup.

* en/header-split-cache-h-part-3: (28 commits)
  fsmonitor-ll.h: split this header out of fsmonitor.h
  hash-ll, hashmap: move oidhash() to hash-ll
  object-store-ll.h: split this header out of object-store.h
  khash: name the structs that khash declares
  merge-ll: rename from ll-merge
  git-compat-util.h: remove unneccessary include of wildmatch.h
  builtin.h: remove unneccessary includes
  list-objects-filter-options.h: remove unneccessary include
  diff.h: remove unnecessary include of oidset.h
  repository: remove unnecessary include of path.h
  log-tree: replace include of revision.h with simple forward declaration
  cache.h: remove this no-longer-used header
  read-cache*.h: move declarations for read-cache.c functions from cache.h
  repository.h: move declaration of the_index from cache.h
  merge.h: move declarations for merge.c from cache.h
  diff.h: move declaration for global in diff.c from cache.h
  preload-index.h: move declarations for preload-index.c from elsewhere
  sparse-index.h: move declarations for sparse-index.c from cache.h
  name-hash.h: move declarations for name-hash.c from cache.h
  run-command.h: move declarations for run-command.c from cache.h
  ...

repository.h

@@ -1,8 +1,6 @@
 #ifndef REPOSITORY_H
 #define REPOSITORY_H
 
-#include "path.h"
-
 struct config_set;
 struct fsmonitor_settings;
 struct git_hash_algo;
@@ -180,6 +178,9 @@ struct repository {
 };
 
 extern struct repository *the_repository;
+#ifdef USE_THE_INDEX_VARIABLE
+extern struct index_state the_index;
+#endif
 
 /*
  * Define a custom repository layout. Any field can be NULL, which
@@ -231,9 +232,6 @@ int repo_hold_locked_index(struct repository *repo,
 			   struct lock_file *lf,
 			   int flags);
 
-int repo_read_index_preload(struct repository *,
-			    const struct pathspec *pathspec,
-			    unsigned refresh_flags);
 int repo_read_index_unmerged(struct repository *);
 /*
  * Opportunistically update the index but do not complain if we can't.