[es7] implement |do| expressions proposal

src/ast-numbering.cc

Index: src/ast-numbering.cc
diff --git a/src/ast-numbering.cc b/src/ast-numbering.cc
index c328ef1efd38ea1cc64fb62670724f70608f5abb..0acd44c2bda61d78fa8e34f40f8df77854338ae8 100644
--- a/src/ast-numbering.cc
+++ b/src/ast-numbering.cc
@@ -132,6 +132,17 @@ void AstNumberingVisitor::VisitNativeFunctionLiteral(
 }
 
 
+void AstNumberingVisitor::VisitDoExpression(DoExpression* node) {
+  IncrementNodeCount();
+  node->set_base_id(ReserveIdRange(DoExpression::num_ids()));
+  if (node->result()->is_assigned()) {
+    Visit(node->result());
+  }
+  VisitDeclarations(node->scope()->declarations());
+  VisitStatements(node->statements());
+}
+
+
 void AstNumberingVisitor::VisitLiteral(Literal* node) {
   IncrementNodeCount();
   node->set_base_id(ReserveIdRange(Literal::num_ids()));