tl2020 pretest begin

[Akira Kakuto]

Hi Karl,

> In any case please fix these symlinks
>    texlua -> luahbtex
>    texluac -> luahbtex
> to point back to luatex as the existing symlinks break context,
> to start with.

I now find that

texlua -> luahbtex
texluac -> luahbtex
texluajit -> luajithbtex
texluajitc -> luajithbtex
probably in all platforms other than Windows.

The above should be
texlua -> luatex
texluac -> luatex
texluajit -> luajittex
texluajitc -> luajittex

Thanks,
Akira