Use ICU case conversion/transliterator for case conversion behind a flag

test/test262/test262.status

Index: test/test262/test262.status
diff --git a/test/test262/test262.status b/test/test262/test262.status
index dddbf134957f00b7f75f2c6fd46fbebcb88f151d..b3c7d3eb03ae9f3e15a49e498bc754b7781c86b3 100644
--- a/test/test262/test262.status
+++ b/test/test262/test262.status
@@ -143,21 +143,11 @@
   'intl402/NumberFormat/11.1.1_1': [FAIL],
 
   # https://code.google.com/p/v8/issues/detail?id=4476
-  'built-ins/String/prototype/toLocaleLowerCase/special_casing_conditional': [FAIL],
-  'built-ins/String/prototype/toLocaleLowerCase/supplementary_plane': [FAIL],
+  # The bug is fixed but behind a flag, --icu_case_mapping.
   'built-ins/String/prototype/toLowerCase/special_casing_conditional': [FAIL],
   'built-ins/String/prototype/toLowerCase/supplementary_plane': [FAIL],
-  'built-ins/String/prototype/toLocaleUpperCase/supplementary_plane': [FAIL],
   'built-ins/String/prototype/toUpperCase/supplementary_plane': [FAIL],
 
-  # https://code.google.com/p/v8/issues/detail?id=4477
-  'intl402/String/prototype/toLocaleLowerCase/special_casing_Azeri': [FAIL],
-  'intl402/String/prototype/toLocaleLowerCase/special_casing_Lithuanian': [FAIL],
-  'intl402/String/prototype/toLocaleLowerCase/special_casing_Turkish': [FAIL],
-  'intl402/String/prototype/toLocaleUpperCase/special_casing_Azeri': [FAIL],
-  'intl402/String/prototype/toLocaleUpperCase/special_casing_Lithuanian': [FAIL],
-  'intl402/String/prototype/toLocaleUpperCase/special_casing_Turkish': [FAIL],
-
   # https://bugs.chromium.org/p/v8/issues/detail?id=4628
   'language/eval-code/non-definable-function-with-variable': [FAIL],
   'language/eval-code/non-definable-function-with-function': [FAIL],
@@ -303,6 +293,22 @@
   'built-ins/String/prototype/normalize/return-normalized-string': [SKIP],
   'built-ins/String/prototype/normalize/return-normalized-string-from-coerced-form': [SKIP],
   'built-ins/String/prototype/normalize/return-normalized-string-using-default-parameter': [SKIP],
+
+  # Case-conversion is not fully compliant to the Unicode spec with i18n off.
+  'built-ins/String/prototype/toLocaleLowerCase/special_casing_conditional': [FAIL],
+  'built-ins/String/prototype/toLocaleLowerCase/supplementary_plane': [FAIL],
+  'built-ins/String/prototype/toLowerCase/special_casing_conditional': [FAIL],
+  'built-ins/String/prototype/toLowerCase/supplementary_plane': [FAIL],
+  'built-ins/String/prototype/toLocaleUpperCase/supplementary_plane': [FAIL],
+  'built-ins/String/prototype/toUpperCase/supplementary_plane': [FAIL],
+
+  # Locale-sensitive case-conversion is not available with i18n off.
+  'intl402/String/prototype/toLocaleLowerCase/special_casing_Azeri': [FAIL],
+  'intl402/String/prototype/toLocaleLowerCase/special_casing_Lithuanian': [FAIL],
+  'intl402/String/prototype/toLocaleLowerCase/special_casing_Turkish': [FAIL],
+  'intl402/String/prototype/toLocaleUpperCase/special_casing_Azeri': [FAIL],
+  'intl402/String/prototype/toLocaleUpperCase/special_casing_Lithuanian': [FAIL],
+  'intl402/String/prototype/toLocaleUpperCase/special_casing_Turkish': [FAIL],
 }],  # no_i18n == True
 
 ['arch == arm or arch == mipsel or arch == mips or arch == arm64 or arch == mips64 or arch == mips64el', {