Reduce size of HTMLCollection / LiveNodeList / ChildNodeList by 1 word

Source/core/html/CollectionIndexCache.h

 /*
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2014 Samsung Electronics. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 74 matching lines @@
     ALWAYS_INLINE bool isCachedNodeCountValid() const { return m_isLengthCacheValid; }
     ALWAYS_INLINE unsigned cachedNodeCount() const { return m_cachedNodeCount; }
     ALWAYS_INLINE void setCachedNodeCount(unsigned length)
     {
         m_cachedNodeCount = length;
         m_isLengthCacheValid = true;
     }
 
     RawPtrWillBeMember<NodeType> m_currentNode;
     unsigned m_cachedNodeCount;
-    unsigned m_cachedNodeIndex;
+    unsigned m_cachedNodeIndex : 31;
     unsigned m_isLengthCacheValid : 1;
 };
 
 template <typename Collection, typename NodeType>
 CollectionIndexCache<Collection, NodeType>::CollectionIndexCache()
     : m_currentNode(nullptr)
     , m_cachedNodeCount(0)
     , m_cachedNodeIndex(0)
     , m_isLengthCacheValid(false)
 {
@@ skipping 93 matching lines @@
         setCachedNodeCount(currentIndex + 1);
         return 0;
     }
     setCachedNode(currentNode, currentIndex);
     return currentNode;
 }
 
 } // namespace WebCore
 
 #endif // CollectionIndexCache_h