Code copy of older Mozilla code

[Emilio Pozuelo Monfort]

Hi Moritz,

Laurent spoke to Mike regarding this and Mike said he was thinking/planning on
dropping libmozjs packages from src:iceweasel (please correct. The only possible
alternative is to have a code copy as a separate source package (as we have done
with mozjs and now with mozjs17). Note that depending on mozjs from iceweasel
would have a big impact on stable when iceweasel is upgraded.

I don't think this is a big problem. At least for my use case (gjs & gnome-shell
and a few other gnome apps) the executed javascript code is the application code
shipped in their packages, not some random webpages. So we're not exposed to
malicious code.

Regards,
Emilio