Remove circular dependency in fluent-langneg (#545)

The circular dependency caused fluent-langneg to not be usable in Vite
and likely other bundlers. It also caused a warning to show up in Rollup.

fixes #459

Author: pago

fluent-langneg/src/locale.ts

@@ -1,7 +1,5 @@
 /* eslint no-magic-numbers: 0 */
 
-import {getLikelySubtagsMin} from "./subtags";
-
 const languageCodeRe = "([a-z]{2,3}|\\*)";
 const scriptCodeRe = "(?:-([a-z]{4}|\\*))";
 const regionCodeRe = "(?:-([a-z]{2}|\\*))";
@@ -108,3 +106,67 @@ export class Locale {
     return false;
   }
 }
+
+
+/**
+ * Below is a manually a list of likely subtags corresponding to Unicode
+ * CLDR likelySubtags list.
+ * This list is curated by the maintainers of Project Fluent and is
+ * intended to be used in place of the full likelySubtags list in use cases
+ * where full list cannot be (for example, due to the size).
+ *
+ * This version of the list is based on CLDR 30.0.3.
+ */
+const likelySubtagsMin: Record<string, string> = {
+  "ar": "ar-arab-eg",
+  "az-arab": "az-arab-ir",
+  "az-ir": "az-arab-ir",
+  "be": "be-cyrl-by",
+  "da": "da-latn-dk",
+  "el": "el-grek-gr",
+  "en": "en-latn-us",
+  "fa": "fa-arab-ir",
+  "ja": "ja-jpan-jp",
+  "ko": "ko-kore-kr",
+  "pt": "pt-latn-br",
+  "sr": "sr-cyrl-rs",
+  "sr-ru": "sr-latn-ru",
+  "sv": "sv-latn-se",
+  "ta": "ta-taml-in",
+  "uk": "uk-cyrl-ua",
+  "zh": "zh-hans-cn",
+  "zh-hant": "zh-hant-tw",
+  "zh-hk": "zh-hant-hk",
+  "zh-gb": "zh-hant-gb",
+  "zh-us": "zh-hant-us",
+};
+
+const regionMatchingLangs = [
+  "az",
+  "bg",
+  "cs",
+  "de",
+  "es",
+  "fi",
+  "fr",
+  "hu",
+  "it",
+  "lt",
+  "lv",
+  "nl",
+  "pl",
+  "ro",
+  "ru",
+];
+
+function getLikelySubtagsMin(loc: string): Locale | null {
+  if (Object.prototype.hasOwnProperty.call(likelySubtagsMin, loc)) {
+    return new Locale(likelySubtagsMin[loc]);
+  }
+  const locale = new Locale(loc);
+  if (locale.language && regionMatchingLangs.includes(locale.language)) {
+    locale.region = locale.language.toUpperCase();
+    return locale;
+  }
+  return null;
+}