ConcurrentMapFactory does not allow use of V8 maps with Sun JDK 6

   static {
      boolean sunIncompatibleJvm;
      boolean jdk8;
      boolean allowExperimentalMap = Boolean.getBoolean("infinispan.unsafe.allow_jdk8_chm");

      try {
         Class.forName("com.sun.unsafe.Unsafe");
         sunIncompatibleJvm = false;
      } catch (ClassNotFoundException e) {
         sunIncompatibleJvm = true;
      }
      
      try {
         Class.forName("java.util.concurrent.atomic.LongAdder");
         jdk8 = true;
      } catch (ClassNotFoundException e) {
         jdk8 = false;
      }

      if (jdk8 || sunIncompatibleJvm || !allowExperimentalMap)
         MAP_CREATOR = new JdkConcurrentMapCreator();
      else
         MAP_CREATOR = new BackportedV8ConcurrentMapCreator();
   }