Turn on icu_case_mapping by default

src/flag-definitions.h

Index: src/flag-definitions.h
diff --git a/src/flag-definitions.h b/src/flag-definitions.h
index abfa3d779bcbac95720d2641a9165223a91c0861..3d58f4e8a5b7aea8fcef22f0fc03c06b72b47f33 100644
--- a/src/flag-definitions.h
+++ b/src/flag-definitions.h
@@ -205,7 +205,7 @@ DEFINE_IMPLICATION(es_staging, move_object_start)
   V(harmony_object_rest_spread, "harmony object rest spread properties")
 
 // Features that are complete (but still behind --harmony/es-staging flag).
-#define HARMONY_STAGED_BASE(V)                              \
+#define HARMONY_STAGED(V)                                   \
   V(harmony_regexp_lookbehind, "harmony regexp lookbehind") \
   V(harmony_restrictive_generators,                         \
     "harmony restrictions on generator declarations")       \
@@ -213,21 +213,14 @@ DEFINE_IMPLICATION(es_staging, move_object_start)
   V(harmony_trailing_commas,                                \
     "harmony trailing commas in function parameter lists")
 
-#ifdef V8_I18N_SUPPORT
-#define HARMONY_STAGED(V)                                          \
-  HARMONY_STAGED_BASE(V)                                           \
-  V(icu_case_mapping, "case mapping with ICU rather than Unibrow")
-#else
-#define HARMONY_STAGED(V) HARMONY_STAGED_BASE(V)
-#endif
-
 // Features that are shipping (turned on by default, but internal flag remains).
 #define HARMONY_SHIPPING_BASE(V)
 
 #ifdef V8_I18N_SUPPORT
-#define HARMONY_SHIPPING(V) \
-  HARMONY_SHIPPING_BASE(V)  \
-  V(datetime_format_to_parts, "Intl.DateTimeFormat.formatToParts")
+#define HARMONY_SHIPPING(V)                                        \
+  HARMONY_SHIPPING_BASE(V)                                         \
+  V(datetime_format_to_parts, "Intl.DateTimeFormat.formatToParts") \
+  V(icu_case_mapping, "case mapping with ICU rather than Unibrow")
 #else
 #define HARMONY_SHIPPING(V) HARMONY_SHIPPING_BASE(V)
 #endif