[luatex] Misplaced letter

[Javier Bezos]

> You need to use a newer fontloader.
>
> Please try the experimental luaotfload:

With it (the patched one) everything seems fine, and
the babel samples in GitHub are rendered as expected
( https://github.com/latex3/latex2e/tree/master/required/babel/samples )
with Amiri, FreeSerif, and Arabic Typesetting, but
I'm still doing some tests (well, Amiri has some
problems, but they are unrelated - the point is the
letters aren't misplaced).

Javier