[clang] [clang-sycl-linker] Replace llvm-link with API calls (PR #133797)

[Arvind Sudarsanam via cfe-commits]

asudarsa wrote:

@jhuber6 

Can you please take a look? This is one of the many changes we are making to upstream SYCL.

Thanks

https://github.com/llvm/llvm-project/pull/133797