Make snapshots 32 or 64 bit compliant by using Write<int64_t> and Read<int64_t> for intptr_t type...

vm/bitfield.h

 // Copyright (c) 2011, 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_BITFIELD_H_
 #define VM_BITFIELD_H_
 
 namespace dart {
 
+static const uword kUwordOne = 1U;
+
 // BitField is a template for encoding and decoding a bit field inside
 // an unsigned machine word.
 template<typename T, int position, int size>
 class BitField {
  public:
   // Tells whether the provided value fits into the bit field.
   static bool is_valid(T value) {
-    return (static_cast<uword>(value) & ~((1U << size) - 1)) == 0;
+    return (static_cast<uword>(value) & ~((kUwordOne << size) - 1)) == 0;
   }
 
   // Returns a uword mask of the bit field.
   static uword mask() {
-    return (1U << size) - 1;
+    return (kUwordOne << size) - 1;
   }
 
   // Returns a uword mask of the bit field which can be applied directly to
   // to the raw unshifted bits.
   static uword mask_in_place() {
-    return ((1U << size) - 1) << position;
+    return ((kUwordOne << size) - 1) << position;
   }
 
   // Returns the shift count needed to right-shift the bit field to
   // the least-significant bits.
   static int shift() {
     return position;
   }
 
   // Returns the size of the bit field.
   static int bitsize() {
     return size;
   }
 
   // Returns a uword with the bit field value encoded.
   static uword encode(T value) {
     ASSERT(is_valid(value));
     return static_cast<uword>(value) << position;
   }
 
   // Extracts the bit field from the value.
   static T decode(uword value) {
-    return static_cast<T>((value >> position) & ((1U << size) - 1));
+    return static_cast<T>((value >> position) & ((kUwordOne << size) - 1));
   }
 
   // Returns a uword with the bit field value encoded based on the
   // original value. Only the bits corresponding to this bit field
   // will be changed.
   static uword update(T value, uword original) {
     ASSERT(is_valid(value));
     return (static_cast<uword>(value) << position) |
         (~mask_in_place() & original);
   }
 };
 
 }  // namespace dart
 
 #endif  // VM_BITFIELD_H_