Partial revert of rest parameter desugaring.

src/ast/ast-value-factory.h

Index: src/ast/ast-value-factory.h
diff --git a/src/ast/ast-value-factory.h b/src/ast/ast-value-factory.h
index ec9a8e389fb18cd6f0b6ea53b13061a6cbdebd4a..560c083a24d39cc8cb89513634d4458b9ddb8146 100644
--- a/src/ast/ast-value-factory.h
+++ b/src/ast/ast-value-factory.h
@@ -261,6 +261,7 @@ class AstValue : public ZoneObject {
   F(next, "next")                               \
   F(proto, "__proto__")                         \
   F(prototype, "prototype")                     \
+  F(rest_parameter, ".rest_parameter")          \
   F(this, "this")                               \
   F(this_function, ".this_function")            \
   F(undefined, "undefined")                     \