Guard khr_group_interface with new macro

Functionality guarded by __DPCPP_ENABLE_UNFINISHED_KHR_EXTENSIONS,
following the process introduced by intel#16883.

Signed-off-by: John Pennycook <[email protected]>

Author: Pennycook

sycl/include/sycl/khr/group_interface.hpp

@@ -6,6 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 #pragma once
+#ifdef __DPCPP_ENABLE_UNFINISHED_KHR_EXTENSIONS
 
 #include <sycl/ext/oneapi/free_function_queries.hpp>
 #include <sycl/id.hpp>
@@ -224,3 +225,5 @@ template <typename Group> bool leader_of(Group g) {
 } // namespace khr
 } // namespace _V1
 } // namespace sycl
+
+#endif // __DPCPP_ENABLE_UNFINISHED_KHR_EXTENSIONS

sycl/test-e2e/GroupInterface/leader_of.cpp

@@ -5,6 +5,7 @@
 #include <iostream>
 #include <sycl/detail/core.hpp>
 #include <sycl/group_algorithm.hpp>
+#define __DPCPP_ENABLE_UNFINISHED_KHR_EXTENSIONS
 #include <sycl/khr/group_interface.hpp>
 
 using namespace sycl;

sycl/test-e2e/GroupInterface/sub_group.cpp

@@ -4,6 +4,7 @@
 // RUN: %{run} %t.out
 
 #include <sycl/detail/core.hpp>
+#define __DPCPP_ENABLE_UNFINISHED_KHR_EXTENSIONS
 #include <sycl/khr/group_interface.hpp>
 
 #include <sycl/builtins.hpp>

sycl/test-e2e/GroupInterface/work_group.cpp

@@ -4,6 +4,7 @@
 // RUN: %{run} %t.out
 
 #include <sycl/detail/core.hpp>
+#define __DPCPP_ENABLE_UNFINISHED_KHR_EXTENSIONS
 #include <sycl/khr/group_interface.hpp>
 
 #include <sycl/builtins.hpp>