[NFC][OpenMP] Add test checking clang offload chunking policy (#83261)

Verify how clang handles `dist_schedule(static, block_chunk)` and
`schedule(static, thread_chunk)` clauses for OpenMP offload loop
workshare pragmas.

GitOrigin-RevId: b9a41b9e9b1441a7b0ca0fb95b9184f73bbfd4b5
1 file changed