add checks for OpenCL C versions (#968)

* add test_compiler test for OpenCL C versions

* add checks for required OpenCL C versions

* bugfix: only OpenCL C 2.0 is required for OpenCL 2.1 and 2.2

* pass reference to feature struct vs. pointer

* address review comments regarding C++ identifiers and 3d image writes

test_common/harness/featureHelpers.h

@@ -0,0 +1,43 @@
+//
+// Copyright (c) 2020 The Khronos Group Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+#ifndef _featureHelpers_h
+#define _featureHelpers_h
+
+#include "compat.h"
+#include "testHarness.h"
+
+struct OpenCLCFeatures
+{
+    bool supports__opencl_c_3d_image_writes;
+    bool supports__opencl_c_atomic_order_acq_rel;
+    bool supports__opencl_c_atomic_order_seq_cst;
+    bool supports__opencl_c_atomic_scope_device;
+    bool supports__opencl_c_atomic_scope_all_devices;
+    bool supports__opencl_c_device_enqueue;
+    bool supports__opencl_c_generic_address_space;
+    bool supports__opencl_c_fp64;
+    bool supports__opencl_c_images;
+    bool supports__opencl_c_int64;
+    bool supports__opencl_c_pipes;
+    bool supports__opencl_c_program_scope_global_variables;
+    bool supports__opencl_c_read_write_images;
+    bool supports__opencl_c_subgroups;
+    bool supports__opencl_c_work_group_collective_functions;
+};
+
+int get_device_cl_c_features(cl_device_id device, OpenCLCFeatures& features);
+
+#endif // _featureHelpers_h