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

test/test262/test262.status

 # Copyright 2011 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 125 matching lines @@
   'built-ins/RegExp/prototype/Symbol.split/str-result-get-length-err': [SKIP],
 
   ###### END REGEXP SUBCLASSING SECTION ######
 
   # https://code.google.com/p/v8/issues/detail?id=4360
   'intl402/Collator/10.1.1_1': [FAIL],
   'intl402/DateTimeFormat/12.1.1_1': [FAIL],
   '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],
 
   # https://bugs.chromium.org/p/v8/issues/detail?id=4592
   'built-ins/ArrayBuffer/length-is-absent': [FAIL],
   'built-ins/ArrayBuffer/length-is-not-number': [FAIL],
   'built-ins/ArrayBuffer/positive-integer-length': [FAIL],
   'language/statements/class/subclass/builtin-objects/ArrayBuffer/regular-subclassing': [FAIL],
 
@@ skipping 125 matching lines @@
   # Unicode canonicalization is not available with i18n turned off.
   'built-ins/String/prototype/localeCompare/15.5.4.9_CE': [SKIP],
 
   # Unicode regexp case mapping is not available with i18n turned off.
   'language/literals/regexp/u-case-mapping': [SKIP],
 
   # BUG(v8:4437).
   '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', {
 
   # TODO(mstarzinger): Causes stack overflow on simulators due to eager
   # compilation of parenthesized function literals. Needs investigation.
   'language/statements/function/S13.2.1_A1_T1': [SKIP],
 
   # BUG(3251225): Tests that timeout with --nocrankshaft.
   'built-ins/decodeURI/S15.1.3.1_A2.4_T1': [SKIP],
@@ skipping 10 matching lines @@
   'built-ins/Promise/prototype/then/deferred-is-resolved-value': [SKIP],
 }],  # asan == True
 
 ['asan == True or msan == True or tsan == True', {
   # https://bugs.chromium.org/p/v8/issues/detail?id=4639
   # The failed allocation causes an asan/msan/tsan error
   'built-ins/ArrayBuffer/allocation-limit': [SKIP],
 }],  # asan == True or msan == True or tsan == True
 
 ]