A later patch in this series will need to know the path to the trash
directory early in 'test-lib.sh', but $TRASH_DIRECTORY is set much
later.
Set $TRASH_DIRECTORY earlier, where the other test-specific path
variables are set.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>