[libclc] Add license headers to files missing them (llvm#132239)

This commit bulk updates all '.h', '.cl', '.inc', and '.cpp' files to
add any missing license headers.

The remaining files are generally CMake, SOURCES, scripts, markdown,
etc.

There are still some '.ll' files which may benefit from a license
header. I can't find an example of an LLVM IR file with a license header
in the rest of LLVM, but unlike most other (sub)projects, libclc has
examples of LLVM IR as source files, compiled and built into the
library.

Author: frasercrmck

libclc/amdgcn-amdhsa/lib/workitem/get_global_size.cl

@@ -1,3 +1,11 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 <clc/clc.h>
 
 #if __clang_major__ >= 8

libclc/amdgcn-amdhsa/lib/workitem/get_local_size.cl

@@ -1,3 +1,11 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 <clc/clc.h>
 
 #if __clang_major__ >= 8

libclc/amdgcn-amdhsa/lib/workitem/get_num_groups.cl

@@ -1,3 +1,11 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 <clc/clc.h>
 

libclc/amdgcn/lib/math/fmax.cl

@@ -1,3 +1,11 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 <clc/clc.h>
 #include <clc/clcmacro.h>
 

libclc/amdgcn/lib/math/fmin.cl

@@ -1,3 +1,11 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 <clc/clc.h>
 #include <clc/clcmacro.h>
 

libclc/amdgcn/lib/mem_fence/fence.cl

@@ -1,3 +1,11 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 <clc/clc.h>
 
 void __clc_amdgcn_s_waitcnt(unsigned flags);

libclc/amdgcn/lib/synchronization/barrier.cl

@@ -1,3 +1,11 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 <clc/clc.h>
 
 _CLC_DEF _CLC_OVERLOAD void barrier(cl_mem_fence_flags flags) {

libclc/amdgcn/lib/workitem/get_global_offset.cl

@@ -1,3 +1,11 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 <clc/clc.h>
 
 #if __clang_major__ >= 8

libclc/amdgcn/lib/workitem/get_global_size.cl

@@ -1,3 +1,11 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 <clc/clc.h>
 
 _CLC_DEF _CLC_OVERLOAD size_t get_global_size(uint dim) {

libclc/amdgcn/lib/workitem/get_group_id.cl

@@ -1,3 +1,11 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 <clc/clc.h>
 
 _CLC_DEF _CLC_OVERLOAD size_t get_group_id(uint dim) {