Missing operator== for xt::fixed_shape #2376

#define XTENSOR_ENABLE_ASSERT 1
#include <xtensor/xfixed.hpp>

void test()
{
  xt::xtensor_fixed<int, xt::xshape<3>> a = {1,2,3};
  std::cout << xt::all(a <= 3) << std::endl;
}

xtensor/xiterator.hpp:1118:38: error: invalid operands to binary expression ('const xt::fixed_shape<3>' and 'const xt::fixed_shape<3>')
        XTENSOR_ASSERT(this->shape() == rhs.shape());