`Plurals` doesn't work for some locales

[movermeyer]

Problem

The Plurals component only outputs a plurals.rb file for a locale if the locale appears exactly in the supplemental/plurals.xml file.

For example, zh-Hant doesn't have a plurals.rb file, which means that it would fall back to its parent locale, root. root happens to have the same plural rules as zh-Hant (i.e., everything uses other) so it isn't an issue.

However, there are locales that fall back to root that don't share the same plural rules as root. For example, sd-Deva falls back to root, but (as I understand it) sd-Deva uses both one and other. So if it were to use root's plurals.rb, it would be incorrect.

Potential Solution?

IDK yet.