Tiff previews causing fatal UTF-8 decoding errors with luatex

[davidcarlisle]

https://tex.stackexchange.com/a/735446/1090

A Tiff preview is a block of bnary data at the start of a EPS file. TeX just has to get past it without error to find the %%BoundingBox
In classic TeX this is achieved by making all characters have a safe catcode, but in luatex the UTF-8 decoder acts earlier and issues an error,.
The same would be true with xetex except there the bytes are replace by a Uniocde Replacement character with just a log info warning.

This could be addressed in the graphics package core EPS reader, but mostly backend specific code is kept out of there so I would propose
to fix in dvips.def in this repository.