Fix an off-by-one error in deoptimization compression.

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 2922 matching lines @@
   intptr_t FromIndex(intptr_t index) const;
   intptr_t ToIndex(intptr_t index) const {
     return index;
   }
 
   // Unpack the entire translation into an array of deoptimization
   // instructions.  This copies any shared suffixes into the array.
   void ToInstructions(const Array& table,
                       GrowableArray<DeoptInstr*>* instructions) const;
 
+
+  // Returns true iff decompression yields the same instructions as the
+  // original.
+  bool VerifyDecompression(const GrowableArray<DeoptInstr*>& original,
+                           const Array& deopt_table) const;
+
  private:
   intptr_t* EntryAddr(intptr_t index, intptr_t entry_offset) const {
     ASSERT((index >=0) && (index < Length()));
     intptr_t data_index = (index * kNumberOfEntries) + entry_offset;
     return &raw_ptr()->data_[data_index];
   }
 
   void SetLength(intptr_t value) const;
 
   FINAL_HEAP_OBJECT_IMPLEMENTATION(DeoptInfo, Object);
@@ skipping 3209 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_