Fix tree shaking being too aggressive

[ThierryBerger]

Fix #278

[sebcrozet]

Looking good. Can you please check if there is any package difference (with our compat and non-compat builds) with and without that change?

Rapier’s packages is already know for being quite big so I wouldn’t want to make it even bigger just to fit one bundler (in which case we would have to figure out a way to make this a special-case rather than apply to all the bundlers).

[ThierryBerger]

Here is the diff while running testbed3:

• This PR (2e92aa0):

• Master (262c307) :

It might be interesting to consider running on a smaller project, from my understanding that's where threeshaking could be useful: removing functions detected as not used.

[sebcrozet]

Looking good, thanks. Ready to merge after the changelog is updated.