Fix bug in optimization in the presence of externalized strings.

runtime/vm/object.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_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 2971 matching lines @@
   // Returns this->raw() if num_args_tested == 1 and arg_nr == 1, otherwise
   // returns a new ICData object containing only unique arg_nr checks.
   RawICData* AsUnaryClassChecksForArgNr(intptr_t arg_nr) const;
   RawICData* AsUnaryClassChecks() const {
     return AsUnaryClassChecksForArgNr(0);
   }
 
   bool AllTargetsHaveSameOwner(intptr_t owner_cid) const;
   bool AllReceiversAreNumbers() const;
   bool HasOneTarget() const;
+  bool HasReceiverClassId(intptr_t class_id) const;
 
   static RawICData* New(const Function& caller_function,
                         const String& target_name,
                         intptr_t deopt_id,
                         intptr_t num_args_tested);
 
   static intptr_t TestEntryLengthFor(intptr_t num_args);
 
   static intptr_t TargetIndexFor(intptr_t num_args) {
     return num_args;
@@ skipping 3272 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_