Reland "[Intl] Fix legacy error handling"

This is a reland of 1f5ab936

Tests started passing before this was reverted so this isn't
culprit.

Original change's description:
> [Intl] Fix legacy error handling
>
> Bug: v8:5751
> Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
> Change-Id: I382404f4c59c1e997ea0fb58f3a995b653c0d6bc
> Reviewed-on: https://chromium-review.googlesource.com/1148031
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#54625}

TBR: jgruber@chromium.org
Bug: v8:5751
Change-Id: I546b10e5cbbbac3aa947ca55cea1f7cc4ae77270
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/1148660Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54672}

src/js/intl.js

@@ -804,14 +804,7 @@ function canonicalizeLanguageTag(localeID) {
   }
 
   // ECMA 402 6.2.3
-  var tag = %CanonicalizeLanguageTag(localeString);
-  // TODO(jshin): This should not happen because the structural validity
-  // is already checked. If that's the case, remove this.
-  if (tag === 'invalid-tag') {
-    throw %make_range_error(kInvalidLanguageTag, localeString);
-  }
-
-  return tag;
+  return %CanonicalizeLanguageTag(localeString);
 }
 
 

src/runtime/runtime-intl.cc

@@ -55,13 +55,14 @@ namespace internal {
 // ECMA 402 6.2.3
 RUNTIME_FUNCTION(Runtime_CanonicalizeLanguageTag) {
   HandleScope scope(isolate);
-  v8::Isolate* v8_isolate = reinterpret_cast<v8::Isolate*>(isolate);
-
-  Factory* factory = isolate->factory();
 
   DCHECK_EQ(1, args.length());
   CONVERT_ARG_HANDLE_CHECKED(String, locale_id_str, 0);
 
+  v8::Isolate* v8_isolate = reinterpret_cast<v8::Isolate*>(isolate);
+
+  Factory* factory = isolate->factory();
+
   v8::String::Utf8Value locale_id(v8_isolate,
                                   v8::Utils::ToLocal(locale_id_str));
 
@@ -72,15 +73,14 @@ RUNTIME_FUNCTION(Runtime_CanonicalizeLanguageTag) {
   // handle long locale names better. See
   // https://ssl.icu-project.org/trac/ticket/13417 .
 
-  // Return value which denotes invalid language tag.
-  const char* const kInvalidTag = "invalid-tag";
-
   UErrorCode error = U_ZERO_ERROR;
   char icu_result[ULOC_FULLNAME_CAPACITY];
   uloc_forLanguageTag(*locale_id, icu_result, ULOC_FULLNAME_CAPACITY, nullptr,
                       &error);
   if (U_FAILURE(error) || error == U_STRING_NOT_TERMINATED_WARNING) {
-    return *factory->NewStringFromAsciiChecked(kInvalidTag);
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate,
+        NewRangeError(MessageTemplate::kInvalidLanguageTag, locale_id_str));
   }
 
   char result[ULOC_FULLNAME_CAPACITY];
@@ -89,9 +89,12 @@ RUNTIME_FUNCTION(Runtime_CanonicalizeLanguageTag) {
   uloc_toLanguageTag(icu_result, result, ULOC_FULLNAME_CAPACITY, TRUE, &error);
 
   if (U_FAILURE(error) || error == U_STRING_NOT_TERMINATED_WARNING) {
-    return *factory->NewStringFromAsciiChecked(kInvalidTag);
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate,
+        NewRangeError(MessageTemplate::kInvalidLanguageTag, locale_id_str));
   }
 
+  DCHECK_NOT_NULL(result);
   return *factory->NewStringFromAsciiChecked(result);
 }