Use Object::null_instance and Object::null_function and do not create Handles everytime.

runtime/vm/parser.cc

 // 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.
 
 #include "vm/parser.h"
 
 #include "lib/invocation_mirror.h"
 #include "platform/utils.h"
 #include "vm/ast_transformer.h"
 #include "vm/bootstrap.h"
@@ skipping 5387 matching lines @@
     if (library_.LookupLocalObject(accessor_name) != Object::null()) {
       ReportError(name_pos, "setter for '%s' is already defined",
                   var_name.ToCString());
     }
 
     const bool is_reflectable =
         !(library_.is_dart_scheme() && library_.IsPrivate(var_name));
     field = Field::New(var_name, is_static, is_final, is_const, is_reflectable,
                        current_class(), name_pos);
     field.set_type(type);
-    field.set_value(Instance::Handle(Z, Instance::null()));
+    field.set_value(Object::null_instance());
     top_level->fields.Add(field);
     library_.AddObject(field, var_name);
     if (metadata_pos >= 0) {
       library_.AddFieldMetadata(field, metadata_pos);
     }
     if (CurrentToken() == Token::kASSIGN) {
       ConsumeToken();
       Instance& field_value = Instance::Handle(Z, Object::sentinel().raw());
       bool has_simple_literal = false;
       if (LookaheadToken(1) == Token::kSEMICOLON) {
@@ skipping 8649 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart