Replace C++ bitfields with our own BitFields

src/unicode.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_UNICODE_H_
 #define V8_UNICODE_H_
 
 #include <sys/types.h>
 #include "src/globals.h"
+#include "src/utils.h"
 /**
  * \file
  * Definitions and convenience functions for working with unicode.
  */
 
 namespace unibrow {
 
 typedef unsigned int uchar;
 typedef unsigned char byte;
 
 /**
  * The max length of the result of converting the case of a single
  * character.
  */
 const int kMaxMappingSize = 4;
 
 template <class T, int size = 256>
 class Predicate {
  public:
   inline Predicate() { }
   inline bool get(uchar c);
+
  private:
   friend class Test;
   bool CalculateValue(uchar c);
-  struct CacheEntry {
-    inline CacheEntry() : code_point_(0), value_(0) { }
+  class CacheEntry {
+   public:
+    inline CacheEntry()
+        : bit_field_(CodePointField::encode(0) | ValueField::encode(0)) {}
     inline CacheEntry(uchar code_point, bool value)
-      : code_point_(code_point),
-        value_(value) { }
-    uchar code_point_ : 21;
-    bool value_ : 1;
+        : bit_field_(CodePointField::encode(code_point) |
+                     ValueField::encode(value)) {}
+
+    uchar code_point() const { return CodePointField::decode(bit_field_); }
+    bool value() const { return ValueField::decode(bit_field_); }
+
+   private:
+    class CodePointField : public v8::internal::BitField<uchar, 0, 21> {};
+    class ValueField : public v8::internal::BitField<bool, 21, 1> {};
+
+    uint32_t bit_field_;
   };
   static const int kSize = size;
   static const int kMask = kSize - 1;
   CacheEntry entries_[kSize];
 };
 
 
 // A cache used in case conversion.  It caches the value for characters
 // that either have no mapping or map to a single character independent
 // of context.  Characters that map to more than one character or that
@@ skipping 154 matching lines @@
   static const int kMaxWidth = 1;
   static int Convert(uchar c,
                      uchar n,
                      uchar* result,
                      bool* allow_caching_ptr);
 };
 
 }  // namespace unibrow
 
 #endif  // V8_UNICODE_H_