Cleanups: int -> intptr_t for "array" lengths, memory sizes.

runtime/vm/bigint_operations.h

 // Copyright 2012 Google Inc. All Rights Reserved.
 
 #ifndef VM_BIGINT_OPERATIONS_H_
 #define VM_BIGINT_OPERATIONS_H_
 
 #include "platform/utils.h"
 
 #include "vm/object.h"
 
 namespace dart {
@@ skipping 130 matching lines @@
   static void DivideRemainder(const Bigint& a, const Bigint& b,
                               Bigint* quotient, Bigint* remainder);
   static Chunk InplaceUnsignedDivideRemainderDigit(
       const Bigint& dividend_quotient, Chunk divisor_digit);
 
   // Removes leading zero-chunks by adjusting the bigint's length.
   static void Clamp(const Bigint& bigint);
 
   static RawBigint* Copy(const Bigint& bigint);
 
-  static int CountBits(Chunk digit);
+  static intptr_t CountBits(Chunk digit);
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(BigintOperations);
 };
 
 }  // namespace dart
 
 #endif  // VM_BIGINT_OPERATIONS_H_