diff: should warn about EOL when --no-index ?

When using `git diff --no-index` on some CRLF files with my setup and config:

    warning: in the working copy of '<something>.csv', CRLF will be replaced by LF the next time Git touches it

To my mind, I’m saying that I don’t care about the working tree per se. In particular, in this case, I’m just using git-diff(1) as a difference utility on some non-Git files (this happens to be outside a Git repository).