[NFC][SYCL][Reduction] Remove dead withAuxHandler (#7217)

Became dead in #6646:
1660a61#diff-b2b881baf4af17b5de77ee38a9f201f59e259d79ccf34463b3695076ec191e03L2408-L2414

Author: aelovikov-intel

sycl/include/sycl/handler.hpp

@@ -351,10 +351,6 @@ tuple_select_elements(TupleT Tuple, std::index_sequence<Is...>);
 
 template <typename T> struct IsReduction;
 template <typename FirstT, typename... RestT> struct AreAllButLastReductions;
-
-template <class FunctorTy>
-event withAuxHandler(std::shared_ptr<detail::queue_impl> Queue, bool IsHost,
-                     FunctorTy Func);
 } // namespace detail
 
 /// Command group handler class.
@@ -485,7 +481,6 @@ class __SYCL_EXPORT handler {
 
   /// Helper utility for operation widely used through different reduction
   /// implementations.
-  /// @{
   template <class FunctorTy>
   event withAuxHandler(std::shared_ptr<detail::queue_impl> Queue,
                        FunctorTy Func) {
@@ -495,11 +490,6 @@ class __SYCL_EXPORT handler {
     return AuxHandler.finalize();
   }
 
-  template <class FunctorTy>
-  friend event detail::withAuxHandler(std::shared_ptr<detail::queue_impl> Queue,
-                                      bool IsHost, FunctorTy Func);
-  /// }@
-
   /// Saves buffers created by handling reduction feature in handler.
   /// They are then forwarded to command group and destroyed only after
   /// the command group finishes the work on device/host.

sycl/include/sycl/reduction.hpp

@@ -68,14 +68,6 @@ template <typename T, class BinaryOperation, int Dims, size_t Extent,
 class reducer;
 
 namespace detail {
-template <class FunctorTy>
-event withAuxHandler(std::shared_ptr<detail::queue_impl> Queue, bool IsHost,
-                     FunctorTy Func) {
-  handler AuxHandler(Queue, IsHost);
-  Func(AuxHandler);
-  return AuxHandler.finalize();
-}
-
 // This type trait is used to detect if the atomic operation BinaryOperation
 // used with operands of the type T is available for using in reduction.
 // The order in which the atomic operations are performed may be arbitrary and