Add numeric_limits min and max for bool

This will allow (among other things) computation of argmax and argmin of bool tensors

Eigen/src/Core/NumTraits.h

@@ -284,6 +284,8 @@ private:
 // Empty specialization for void to allow template specialization based on NumTraits<T>::Real with T==void and SFINAE.
 template<> struct NumTraits<void> {};
 
+template<> NumTraits<bool> : GenericNumTraits<bool> {};
+
 } // end namespace Eigen
 
 #endif // EIGEN_NUMTRAITS_H