worktree: add top-level worktree.c

worktree.c contains functions to work with and get information from
worktrees.  This introduction moves functions related to worktrees
from branch.c into worktree.c

Signed-off-by: Michael Rappazzo <rappazzo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 0 insertions, 8 deletions

diff --git a/branch.h b/branch.h
index d3446ed..58aa45f 100644
--- a/branch.h
+++ b/branch.h
@@ -59,12 +59,4 @@ extern int read_branch_desc(struct strbuf *, const char *branch_name);
  */
 extern void die_if_checked_out(const char *branch);
 
-/*
- * Check if a per-worktree symref points to a ref in the main worktree
- * or any linked worktree, and return the path to the exising worktree
- * if it is.  Returns NULL if there is no existing ref.  The caller is
- * responsible for freeing the returned path.
- */
-extern char *find_shared_symref(const char *symref, const char *target);
-
 #endif