PATCH: "make check" is broken in binutils

[DJ Delorie]

> I am testing this patch.

Don't bother, it's wrong.  The whole point of the maybe-targets is
that you can always depend on them, and they'll decide if they need to
actually do something or not.  So the problem is that maybe-check-gcc
isn't always there, not that you have to assume it's not always there.

> -do-check: maybe-check-gcc [+
> +do-check: @maybe_check_gcc@ [+