Macro icu_calendar_data::impl_calendar_japanext_v1

macro_rules! impl_calendar_japanext_v1 {
    ($ provider : ty) => { ... };
}

Implement DataProvider<JapaneseExtendedErasV1Marker> on the given struct using the data hardcoded in this file. This allows the struct to be used with icu’s _unstable constructors.