[NFC][SYCL] Add device_images_range helper

Author: aelovikov-intel

sycl/source/detail/device_image_impl.hpp

@@ -1341,6 +1341,18 @@ class device_image_impl
   std::unique_ptr<DynRTDeviceBinaryImage> MMergedImageStorage = nullptr;
 };
 
+using device_images_iterator =
+    variadic_iterator<device_image_plain,
+                      std::vector<device_image_plain>::const_iterator,
+                      std::set<device_image_impl *>::const_iterator>;
+class device_images_range : public iterator_range<device_images_iterator> {
+private:
+  using Base = iterator_range<device_images_iterator>;
+
+public:
+  using Base::Base;
+};
+
 } // namespace detail
 } // namespace _V1
 } // namespace sycl

sycl/source/detail/helpers.hpp

@@ -91,6 +91,8 @@ template <typename SyclTy, typename... Iterators> class variadic_iterator {
         },
         It);
   }
+
+  pointer operator->() { return &this->operator*(); }
 };
 
 // Non-owning!