Function normalizeLocale

packages/core/src/i18n/locale_data_api.ts:183–185

* Returns the canonical form of a locale name - lowercase with `_` replaced with `-`.

(locale: string)

 * Returns the canonical form of a locale name - lowercase with `_` replaced with `-`.
 */
function normalizeLocale(locale: string): string {
  return locale.toLowerCase().replace(/_/g, '-');
}