[es6] implement destructuring assignment

src/ast/ast-expression-visitor.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/ast/ast-expression-visitor.h"
 
 #include "src/ast/ast.h"
 #include "src/ast/scopes.h"
@@ skipping 376 matching lines @@
 
 
 void AstExpressionVisitor::VisitSuperCallReference(SuperCallReference* expr) {
   VisitExpression(expr);
   RECURSE_EXPRESSION(VisitVariableProxy(expr->this_var()));
   RECURSE_EXPRESSION(VisitVariableProxy(expr->new_target_var()));
   RECURSE_EXPRESSION(VisitVariableProxy(expr->this_function_var()));
 }
 
 
+void AstExpressionVisitor::VisitRewritableAssignmentExpression(
+    RewritableAssignmentExpression* expr) {
+  VisitExpression(expr);
+  RECURSE(Visit(expr->expression()));
+}
+
+
 }  // namespace internal
 }  // namespace v8