Turn on icu_case_mapping by default

test/webkit/webkit.status

Index: test/webkit/webkit.status
diff --git a/test/webkit/webkit.status b/test/webkit/webkit.status
index afc504fb8d6c749d1076041b19e55649b30da80c..d8477572c8669b2789349d03f54f936ae2fb5881 100644
--- a/test/webkit/webkit.status
+++ b/test/webkit/webkit.status
@@ -126,4 +126,9 @@
 }],  # variant == wasm_traps
 
 ##############################################################################
+['no_i18n == True', {
+  'fast/js/string-capitalization': [FAIL],
+}],  # variant == wasm_traps
+
+##############################################################################
 ]