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

[Arvind Sudarsanam via cfe-commits]

asudarsa wrote:

> Shouldn't we be able to just use LTO after the SPIR-V backend left experimental?

Hi @jhuber6 

Thanks for the ping back. That is the eventual path for us. However, we would like to do it in stages. Replacing llvm-link tool with linkInModule call helps us to achieve one of our initial goals: To replace calls to external tools with library calls, wherever possible. Once we have an end-to-end device code linking available upstream, we should be able to replace linkInModule calls by using LTO.

Thanks

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