Translate `set --` assignments as `set argv`

[Neved4]

In some scripts it's common to use the pseudo-array construct as a substitute for proper arrays when the shell lacks support for them:

set -- x y z

Currently that would make babelfish produce the exact same line, which will break.

Ideally, we'd be translating it to the equivalent:

set argv x y z

See: POSIX.1-2017: §2.15 Special Built-In Utilities