VM: Make ZoneAllocated-objects that don't need a vtable smaller.

runtime/vm/ast.h

 // Copyright (c) 2012, 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 VM_AST_H_
 #define VM_AST_H_
 
 #include "platform/assert.h"
 #include "vm/allocation.h"
 #include "vm/growable_array.h"
@@ skipping 80 matching lines @@
   virtual bool Is##type() const { return true; }                               \
   virtual type* As##type() { return this; }
 
 
 class AstNode : public ZoneAllocated {
  public:
   explicit AstNode(intptr_t token_pos)
       : token_pos_(token_pos) {
     ASSERT(token_pos_ >= 0);
   }
+  virtual ~AstNode() { }
 
   intptr_t token_pos() const { return token_pos_; }
 
 #define AST_TYPE_CHECK(BaseName)                                               \
   virtual bool Is##BaseName##Node() const { return false; }                    \
   virtual BaseName##Node* As##BaseName##Node() { return NULL; }
 
   FOR_EACH_NODE(AST_TYPE_CHECK)
 #undef AST_TYPE_CHECK
 
@@ skipping 1691 matching lines @@
   const intptr_t try_index_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(InlinedFinallyNode);
 };
 
 }  // namespace dart
 
 #undef DECLARE_COMMON_NODE_FUNCTIONS
 
 #endif  // VM_AST_H_