Fixes javascript integer overflow check.

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 4119 matching lines @@
 
   // Returns 0, -1 or 1.
   virtual int CompareWith(const Integer& other) const;
 
   // Return the most compact presentation of an integer.
   RawInteger* AsValidInteger() const;
 
   RawInteger* ArithmeticOp(Token::Kind operation, const Integer& other) const;
   RawInteger* BitOp(Token::Kind operation, const Integer& other) const;
 
-  // Returns true if the Integer does not fit in 53 bits.
-  bool CheckFiftyThreeBitOverflow() const;
+  // Returns true if the Integer does not fit in 54 bits.
+  bool CheckFiftyFourBitOverflow() const;
 
  private:
   // Return an integer in the form of a RawBigint.
   RawBigint* AsBigint() const;
 
   OBJECT_IMPLEMENTATION(Integer, Number);
   friend class Class;
 };
 
 
@@ skipping 1879 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_