[Intl] Work around ICU-8420 for "und"

Fix intl402/Locale/likely-subtags

Bug: v8:8236
Change-Id: I0f109d0bedb1fda3f5eaac9cfce935788f54b595
Reviewed-on: https://chromium-review.googlesource.com/c/1459745Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59476}

src/objects/js-locale.cc

@@ -430,6 +430,10 @@ Handle<String> MorphLocale(Isolate* isolate, String locale,
   UErrorCode status = U_ZERO_ERROR;
   icu::Locale icu_locale =
       icu::Locale::forLanguageTag(locale.ToCString().get(), status);
+  // TODO(ftang): Remove the following lines after ICU-8420 fixed.
+  // Due to ICU-8420 "und" is turn into "" by forLanguageTag,
+  // we have to work around to use icu::Locale("und") directly
+  if (icu_locale.getName()[0] == '\0') icu_locale = icu::Locale("und");
   CHECK(U_SUCCESS(status));
   CHECK(!icu_locale.isBogus());
   (*morph_func)(&icu_locale, &status);

test/test262/test262.status

@@ -516,9 +516,6 @@
   # https://bugs.chromium.org/p/v8/issues/detail?id=8246
   'intl402/Locale/constructor-tag': [FAIL],
 
-  # https://bugs.chromium.org/p/v8/issues/detail?id=8236
-  'intl402/Locale/likely-subtags': [FAIL],
-
   # https://bugs.chromium.org/p/v8/issues/detail?id=8242
   'intl402/Locale/likely-subtags-grandfathered': [FAIL],