MinGW: update tests to handle a native eol of crlf

MinGW: update tests to handle a native eol of crlf

Some of the tests were written with the assumption that the native
eol would always be lf. After defining NATIVE_CRLF on MinGW, these
tests began failing.  This change will update the tests to also
handle a native eol of crlf.

Signed-off-by: Brice Lambson <bricelam@live.com>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>