[libc] [llvm] [LLVM] Port 'llvm-gpu-loader' to use LLVMOffload (PR #162739)

[Jon Chesterfield via llvm-commits]

https://github.com/JonChesterfield approved this pull request.

Yep, let's have this.

All my misgivings with how llvm offload has bee  deployed remain, but this is still a good idea. Happy hunting any bugs that appear.

https://github.com/llvm/llvm-project/pull/162739