Hugo 78bd318c96 Add Locale.toLanguageTag() (#8421)
Adds `Locale.toLanguageTag()`, which returns a valid Unicode Locale Identifier
using underscores as separator that can be reliably parsed.
2019-04-08 11:21:19 -07:00
..
2018-11-07 12:24:35 -08:00
2019-04-08 11:21:19 -07:00