Restrict FunctionDeclarations in Statement position

src/flag-definitions.h

Index: src/flag-definitions.h
diff --git a/src/flag-definitions.h b/src/flag-definitions.h
index 8441a954c5c443d966b58fd177c2cc5be70ca3e5..1de25596ebf6d58d9b7f5548a690793e25c57222 100644
--- a/src/flag-definitions.h
+++ b/src/flag-definitions.h
@@ -204,15 +204,17 @@ DEFINE_IMPLICATION(es_staging, move_object_start)
 DEFINE_IMPLICATION(es_staging, harmony_tailcalls)
 
 // Features that are still work in progress (behind individual flags).
-#define HARMONY_INPROGRESS(V)                                                \
-  V(harmony_object_observe, "harmony Object.observe")                        \
-  V(harmony_modules, "harmony modules")                                      \
-  V(harmony_function_sent, "harmony function.sent")                          \
-  V(harmony_sharedarraybuffer, "harmony sharedarraybuffer")                  \
-  V(harmony_simd, "harmony simd")                                            \
-  V(harmony_do_expressions, "harmony do-expressions")                        \
-  V(harmony_tailcalls, "harmony tail calls")                                 \
-  V(harmony_regexp_property, "harmony unicode regexp property classes")
+#define HARMONY_INPROGRESS(V)                                           \
+  V(harmony_object_observe, "harmony Object.observe")                   \
+  V(harmony_modules, "harmony modules")                                 \
+  V(harmony_function_sent, "harmony function.sent")                     \
+  V(harmony_sharedarraybuffer, "harmony sharedarraybuffer")             \
+  V(harmony_simd, "harmony simd")                                       \
+  V(harmony_do_expressions, "harmony do-expressions")                   \
+  V(harmony_tailcalls, "harmony tail calls")                            \
+  V(harmony_regexp_property, "harmony unicode regexp property classes") \
+  V(harmony_restrictive_declarations,                                   \
+    "harmony limitations on sloppy mode function declarations")
 
 // Features that are complete (but still behind --harmony/es-staging flag).
 #define HARMONY_STAGED(V)                                                    \