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

test/test262/testcfg.py

Index: test/test262/testcfg.py
diff --git a/test/test262/testcfg.py b/test/test262/testcfg.py
index b62e9b0d6b4ffbe99ccb95de871713db440c3e30..3ce14db828f2d423c410295735dbc973ecd3472d 100644
--- a/test/test262/testcfg.py
+++ b/test/test262/testcfg.py
@@ -131,6 +131,7 @@ class Test262TestSuite(testsuite.TestSuite):
     return (testcase.flags + context.mode_flags + self.harness +
             self.GetIncludesForTest(testcase) + ["--harmony"] +
             (["--module"] if "module" in self.GetTestRecord(testcase) else []) +
+            ["--icu_case_mapping"] +
             [os.path.join(self.testroot, testcase.path + ".js")] +
             (["--throws"] if "negative" in self.GetTestRecord(testcase)
                           else []) +