[ESnext] Implement Object spread

src/ast/ast.h

Index: src/ast/ast.h
diff --git a/src/ast/ast.h b/src/ast/ast.h
index 0a4e7481810b541c263d7965fa788375383dded2..1d04eb149e0605caf23ba1e03a0c9199f325fec0 100644
--- a/src/ast/ast.h
+++ b/src/ast/ast.h
@@ -1354,8 +1354,9 @@ class ObjectLiteralProperty final : public LiteralProperty {
     COMPUTED,              // Property with computed value (execution time).
     MATERIALIZED_LITERAL,  // Property value is a materialized literal.
     GETTER,
-    SETTER,    // Property is an accessor function.
-    PROTOTYPE  // Property is __proto__.
+    SETTER,     // Property is an accessor function.
+    PROTOTYPE,  // Property is __proto__.
+    SPREAD
   };
 
   Kind kind() const { return kind_; }