Potential issues detecting RTL

[leakymemory]

It looks like our algorithm for determining if the given locale is an RTL language has a couple of holes. For example, pa-in and pa-arab-pk.

I dug around and this article might be a good reference:
http://stackoverflow.com/questions/4192382/is-there-any-way-to-detect-an-rtl-language-in-java

getIso639P1LocaleCode()

[mttwc]

https://www.npmjs.com/package/rtl-detect doesn't work for pa-arab-pk.