Record whether the underlying tensor storage can be accessed directly during the evaluation of an expression.

unsupported/Eigen/CXX11/src/Tensor/TensorReduction.h

@@ -428,6 +428,7 @@ struct TensorEvaluator<const TensorReductionOp<Op, Dims, ArgType>, Device>
     PacketAccess = Self::InputPacketAccess && Op::PacketAccess,
     Layout = TensorEvaluator<ArgType, Device>::Layout,
     CoordAccess = false,  // to be implemented
+    RawAccess = false
   };
 
   static const bool ReducingInnerMostDims = internal::are_inner_most_dims<Dims, NumInputDims, Layout>::value;