[es7] implement |do| expressions proposal

src/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-expression-visitor.h"
 
 #include "src/ast.h"
 #include "src/codegen.h"
@@ skipping 178 matching lines @@
   VisitExpression(expr);
   RECURSE_EXPRESSION(VisitDeclarations(scope->declarations()));
   RECURSE_EXPRESSION(VisitStatements(expr->body()));
 }
 
 
 void AstExpressionVisitor::VisitNativeFunctionLiteral(
     NativeFunctionLiteral* expr) {}
 
 
+void AstExpressionVisitor::VisitDoExpression(DoExpression* expr) {
+  RECURSE(VisitBlock(expr->block()));
+  RECURSE(VisitVariableProxy(expr->result()));
+}
+
+
 void AstExpressionVisitor::VisitConditional(Conditional* expr) {
   RECURSE(Visit(expr->condition()));
   RECURSE(Visit(expr->then_expression()));
   RECURSE(Visit(expr->else_expression()));
 }
 
 
 void AstExpressionVisitor::VisitVariableProxy(VariableProxy* expr) {
   VisitExpression(expr);
 }
@@ skipping 138 matching lines @@
 
 void AstExpressionVisitor::VisitSuperPropertyReference(
     SuperPropertyReference* expr) {}
 
 
 void AstExpressionVisitor::VisitSuperCallReference(SuperCallReference* expr) {}
 
 
 }  // namespace internal
 }  // namespace v8