[PATCH] Short-circuit git-clone-pack while cloning locally (take 2).

[PATCH] Short-circuit git-clone-pack while cloning locally (take 2).

When we are cloning a repository on a local filesystem, it is
faster to just create a hard linkfarm of .git/object hierarchy
and copy the .git/refs files.  By default, the script uses the
clone-pack method, but it can be told with the -l flag to do the
hard linkfarm (falling back on recursive file copy) to replicate
the .git/object hierarchy.

Signed-off-by: Junio C Hamano <redacted>
Signed-off-by: Linus Torvalds <redacted>