Make fraction and num-bigint an optional dep of datagen

[Manishearth]

cc @younies : Any new dependencies of the non-experimental ICU4X build should probably be discussed. It's fine as long as this component is experimental, but at some point we need to review if this dependency is the best way to achieve this task.

I'd also like to uplift this to 1.4 and release 1.4.1 , thoughts?

• @sffc
• @robertbastian
• @zbraniecki (approved in slack)

[robertbastian]

At 1.4.0, icu_unitsconversion is a dev-dependency. So if you backport it should be that, not an optional dependency.

[Manishearth]

Good to know, thanks!

I think this dependency isn't used for much (f689152#diff-8e479132faa50170b42b40a4093a8c9f397e4b866e1a03d35d2c5e0e2c336514) and I may make a separate PR removing it entirely.

But for 1.4 we should just devdep it.

[Manishearth]

n.b. we are not in a rush to do this

[Manishearth]

I will still merge this regardless since this is not the backport PR. @robertbastian or I will make a backport PR separately.

Though I hope to get rid of this dep entirely

[Manishearth]

autosubmit

[robertbastian]

num_bigint should get the same treatment

[Manishearth]

Updated to optionalify num-bigint as well.

I'm a bit more okay about the num family of crates since we already depend on some of them, but yeah we shouldn't be adding these deps without discussion anyway.

[sffc]

According to @Manishearth the fraction crate contains substantial unsafe code and therefore is a nontrivial import. @Manishearth will make a PR that attempts to remove the fraction dependency.