git-prompt: do not look for refs/stash in $GIT_DIR
git-prompt: do not look for refs/stash in $GIT_DIR

Since dd0b72c (bash prompt: use bash builtins to check stash
state, 2011-04-01), git-prompt checks whether we have a
stash by looking for $GIT_DIR/refs/stash. Generally external
programs should never do this, because they would miss
packed-refs.

That commit claims that packed-refs does not pack
refs/stash, but that is not quite true. It does pack the
ref, but due to a bug, fails to prune the ref. When we fix
that bug, we would want to be doing the right thing here.

Signed-off-by: Jeff King <696e3fbcf235d40b6ea1ebd61c87cbea79d444e7@peff.net>
Reviewed-by: Michael Haggerty <c24c152f145c57791e809b126db9e61bd1c1782d@alum.mit.edu>
Reviewed-by: Ronnie Sahlberg <2cb6c6c4ccf58d41468189c2307f7a4ebf120324@google.com>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

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