[ESnext] Implement Object Rest

src/messages.h

Index: src/messages.h
diff --git a/src/messages.h b/src/messages.h
index 3f3ecce134895b3005d15b45ca2d4f69c568b5db..aaad0e89995624e25a00108cce5252fc14309f45 100644
--- a/src/messages.h
+++ b/src/messages.h
@@ -588,7 +588,7 @@ class ErrorUtils : public AllStatic {
   T(PushPastSafeLength,                                                        \
     "Pushing % elements on an array-like of length % "                         \
     "is disallowed, as the total surpasses 2**53-1")                           \
-  T(ElementAfterRest, "Rest element must be last element in array")            \
+  T(ElementAfterRest, "Rest element must be last element")                     \
   T(BadSetterRestParameter,                                                    \
     "Setter function argument must not be a rest parameter")                   \
   T(ParamDupe, "Duplicate parameter name not allowed in this context")         \