[SYCL][NFC] Ignore unused arguments (#8939)

Signed-off-by: Larsen, Steffen <[email protected]>

Author: steffenlarsen

sycl/include/sycl/reduction.hpp

@@ -2791,6 +2791,7 @@ void reduction_parallel_for(handler &CGH, range<Dims> Range,
 template <typename T, typename AllocatorT, typename BinaryOperation>
 auto reduction(buffer<T, 1, AllocatorT> Var, handler &CGH,
                BinaryOperation Combiner, const property_list &PropList = {}) {
+  std::ignore = CGH;
   bool InitializeToIdentity =
       PropList.has_property<property::reduction::initialize_to_identity>();
   return detail::make_reduction<BinaryOperation, 0, 1, false>(
@@ -2817,6 +2818,7 @@ auto reduction(T *Var, BinaryOperation Combiner,
 template <typename T, typename AllocatorT, typename BinaryOperation>
 auto reduction(buffer<T, 1, AllocatorT> Var, handler &CGH, const T &Identity,
                BinaryOperation Combiner, const property_list &PropList = {}) {
+  std::ignore = CGH;
   bool InitializeToIdentity =
       PropList.has_property<property::reduction::initialize_to_identity>();
   return detail::make_reduction<BinaryOperation, 0, 1, true>(