[es6] implement destructuring assignment

src/ast/ast-numbering.cc

Index: src/ast/ast-numbering.cc
diff --git a/src/ast/ast-numbering.cc b/src/ast/ast-numbering.cc
index 474eec675450d53c74584289cc442fd69b82cfeb..9994aa0a25f073d06065a508125101ff32217817 100644
--- a/src/ast/ast-numbering.cc
+++ b/src/ast/ast-numbering.cc
@@ -348,6 +348,7 @@ void AstNumberingVisitor::VisitProperty(Property* node) {
 void AstNumberingVisitor::VisitAssignment(Assignment* node) {
   IncrementNodeCount();
   node->set_base_id(ReserveIdRange(Assignment::num_ids()));
+
   if (node->is_compound()) VisitBinaryOperation(node->binary_operation());
   VisitReference(node->target());
   Visit(node->value());
@@ -556,6 +557,12 @@ void AstNumberingVisitor::VisitFunctionLiteral(FunctionLiteral* node) {
 }
 
 
+void AstNumberingVisitor::VisitRewritableExpression(
+    RewritableExpression* node) {
+  Visit(node->expression());
+}
+
+
 bool AstNumberingVisitor::Finish(FunctionLiteral* node) {
   node->set_ast_properties(&properties_);
   node->set_dont_optimize_reason(dont_optimize_reason());