Add "S_IFDIRLNK" file mode infrastructure for git links
Add "S_IFDIRLNK" file mode infrastructure for git links

This just adds the basic helper functions to recognize and work with git
tree entries that are links to other git repositories ("subprojects").
They still aren't actually connected up to any of the code-paths, but
now all the infrastructure is in place.

The next commit will start actually adding actual subproject support.

Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>
Signed-off-by: Junio C Hamano <dc50d1021234060e53ec42a77d526afa2fe07479@cox.net>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git