blame: add a failing test for a CRLF issue.

If a file contains CRLF line endings in a repository with
core.autocrlf=input, then blame always marks the lines as "Not Committed
Yet", even if they are unmodified.  Add a failing test for this case, so we
are at least aware of this issue.

Reported-by: Ephrim Khong <dr.khong@gmail.com>
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>