[llvm] WIP: [Offload] Add testing for Offload program and kernel related entry points (PR #127803)

[Joseph Huber via llvm-commits]

================
@@ -0,0 +1,17 @@
+//===------- Offload API tests - helper for test device code --------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
----------------
jhuber6 wrote:

With `<gpuintrin.h>` this looks like
```c
#include <gpuintrin.h>

__gpu_kernel void kernel(uint32_t *out) {
  *out = __gpu_thread_id(0);
}
```

https://github.com/llvm/llvm-project/pull/127803