Reimplement clamp as a static function.

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

diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorMorphing.h b/unsupported/Eigen/CXX11/src/Tensor/TensorMorphing.h
index caf9949..620666c 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorMorphing.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorMorphing.h
@@ -708,9 +708,6 @@
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE TensorEvaluator(const XprType& op, const Device& device)
       : m_impl(op.expression(), device), m_device(device), m_strides(op.strides())
   {
-    auto clamp = [](Index value, Index min, Index max){
-      return numext::maxi(min,numext::mini(max,value));
-    };
     // Handle degenerate intervals by gracefully clamping and allowing m_dimensions to be zero
     DSizes<Index,NumDims> startIndicesClamped, stopIndicesClamped;
     for (int i = 0; i < internal::array_size<Dimensions>::value; ++i) {
@@ -834,6 +831,10 @@
     return inputIndex;
   }
 
+  static EIGEN_STRONG_INLINE Index clamp(Index value, Index min, Index max) {
+    return numext::maxi(min, numext::mini(max,value));
+  }
+
   array<Index, NumDims> m_outputStrides;
   array<internal::TensorIntDivisor<Index>, NumDims> m_fastOutputStrides;
   array<Index, NumDims> m_inputStrides;