Improve --print-ast printing of LetNode.

runtime/vm/ast_printer.h

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef RUNTIME_VM_AST_PRINTER_H_
 #define RUNTIME_VM_AST_PRINTER_H_
 
 #include "vm/ast.h"
 #include "vm/growable_array.h"
 
@@ skipping 26 matching lines @@
                                LocalVariable* var,
                                int indent = 0);
   void PrintLocalScope(const LocalScope* scope,
                        int variable_index,
                        int indent = 0);
 
   void VisitGenericAstNode(AstNode* node);
   void VisitGenericLocalNode(AstNode* node, const LocalVariable& local);
   void VisitGenericFieldNode(AstNode* node, const Field& field);
 
+  void PrintLocalVariable(const LocalVariable* variable);
+  void PrintNewlineAndIndent();
+
   intptr_t indent_;
   Log* logger_;
 
   DISALLOW_COPY_AND_ASSIGN(AstPrinter);
 };
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_AST_PRINTER_H_