Add assertion to max wg size (#2580)

---------

Signed-off-by: Dan Hoeflinger <dan.hoeflinger@intel.com>

Author: danhoeflinger

include/oneapi/dpl/pstl/hetero/dpcpp/parallel_backend_sycl.h

@@ -513,6 +513,7 @@ struct __parallel_copy_if_single_group_functor<__internal::__optional_kernel_nam
     operator()(sycl::queue& __q, _InRng&& __in_rng, _OutRng&& __out_rng, _Size __n, _Size __n_out, _UnaryOp __unary_op,
                _Assign __assign, std::size_t __max_wg_size)
     {
+        assert(__max_wg_size <= std::numeric_limits<std::uint16_t>::max());
         // This type is used as a workaround for when an internal tuple is assigned to std::tuple, such as
         // with zip_iterator
         using __tuple_type = typename oneapi::dpl::__internal::__get_tuple_type<
@@ -922,7 +923,7 @@ __parallel_copy_if(oneapi::dpl::__internal::__device_backend_tag, _ExecutionPoli
     std::array<_Size, 2> __ret = {__n_out, __n};
     sycl::queue __q_local = __exec.queue();
 
-    constexpr std::uint16_t __max_elem_per_item = 2;
+    constexpr std::size_t __max_elem_per_item = 2;
     std::size_t __max_wg_size = oneapi::dpl::__internal::__max_work_group_size(__q_local);
 
     // Note: earlier the data size for the single group kernel was capped by 2048