[SYCL] Added test for deprecated features

.github/CODEOWNERS

@@ -71,3 +71,6 @@ SYCL/USM @jbrodman
 
 # Stream
 SYCL/Basic/stream @againull
+
+# Deprecated features
+SYCL/Deprecated_features @maximdimakov @alexbatashev

SYCL/Deprecated_features/deprecated.cpp

@@ -0,0 +1,27 @@
+// RUN: %clangxx -D__SYCL_INTERNAL_API -fsycl -fsycl-targets=%sycl_triple %s -o %t.out
+// RUN: %CPU_RUN_PLACEHOLDER %t.out
+// RUN: %GPU_RUN_PLACEHOLDER %t.out
+// RUN: %HOST_RUN_PLACEHOLDER %t.out
+// RUN: %ACC_RUN_PLACEHOLDER %t.out
+
+//==------------- deprecated.cpp - SYCL 2020 deprecation test --------------==//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include <CL/sycl.hpp>
+
+using namespace cl::sycl;
+
+int main() {
+  device Device{default_selector()};
+  platform Platform{default_selector()};
+
+  bool b = Device.has_extension("cl_intel_subgroups");
+  b = Platform.has_extension("some_extension");
+
+  return 0;
+}