Ship restriction disallowing duplicate generator declarations in blocks

Bug: v8:4806
Change-Id: I612615f92c56f10a9c53237e0c5da26c527fc6f3
Reviewed-on: https://chromium-review.googlesource.com/478411Reviewed-by: Daniel Ehrenberg <littledan@chromium.org>
Commit-Queue: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44666}

src/flag-definitions.h

@@ -214,15 +214,15 @@ DEFINE_IMPLICATION(es_staging, harmony)
   V(harmony_regexp_lookbehind, "harmony regexp lookbehind")              \
   V(harmony_regexp_named_captures, "harmony regexp named captures")      \
   V(harmony_regexp_property, "harmony unicode regexp property classes")  \
-  V(harmony_restrictive_generators,                                      \
-    "harmony restrictions on generator declarations")                    \
   V(harmony_object_rest_spread, "harmony object rest spread properties") \
   V(harmony_template_escapes,                                            \
     "harmony invalid escapes in tagged template literals")
 
 // Features that are shipping (turned on by default, but internal flag remains).
-#define HARMONY_SHIPPING_BASE(V) \
-  V(harmony_trailing_commas,     \
+#define HARMONY_SHIPPING_BASE(V)                      \
+  V(harmony_restrictive_generators,                   \
+    "harmony restrictions on generator declarations") \
+  V(harmony_trailing_commas,                          \
     "harmony trailing commas in function parameter lists")
 
 #ifdef V8_I18N_SUPPORT