Fix the types used in bit fields.

vm/memory_region.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_MEMORY_REGION_H_
 #define VM_MEMORY_REGION_H_
 
 #include "platform/assert.h"
 #include "vm/globals.h"
 
@@ skipping 48 matching lines @@
     size_ = (region.size() + extra);
   }
 
  private:
   template<typename T> T* ComputeInternalPointer(uword offset) const {
     ASSERT(size() >= sizeof(T));
     ASSERT(offset <= size() - sizeof(T));
     return reinterpret_cast<T*>(start() + offset);
   }
 
-  // Locate the bit with the given offset. Returns a pointer to the byte
-  // containing the bit, and sets bit_mask to the bit within that byte.
-  uint8_t* ComputeBitPointer(uword bit_offset, uint8_t* bit_mask) const {
-    uword bit_remainder = (bit_offset & (kBitsPerByte - 1));
-    *bit_mask = (1U << bit_remainder);
-    uword byte_offset = (bit_offset >> kBitsPerByteLog2);
-    return ComputeInternalPointer<uint8_t>(byte_offset);
-  }
-
   void* pointer_;
   uword size_;
 
   DISALLOW_COPY_AND_ASSIGN(MemoryRegion);
 };
 
 }  // namespace dart
 
 #endif  // VM_MEMORY_REGION_H_