[clang] [Clang][SYCL] Introduce clang-sycl-link-wrapper to link SYCL offloading device code (Part 1 of many) (PR #112245)

[Joseph Huber via cfe-commits]

jhuber6 wrote:

> > Why is this a clang-based tool? Other than using clang/Basic to get the clang version (which could also be retrieved from LLVM), this doesn't seem to have any dependencies on Clang.
> > As I'm seeing the SYCL patches coming in I'm getting concerned that the architecture of the SYCL compiler doesn't align with LLVM and Clang's design.
> 
> Realistically it doesn't need to be, despite the fact that clang wants to use it. The goal is to just have a tool that clang can use as a normal toolchain linker so we can reuse as much as possible when it comes to creating link jobs. We could stash this in `llvm/` and it wouldn't make much of a difference. Also we can probably just use the LLVM Linker API instead of `llvm-link`. Forgot to mention that as a to-do.

I don't know if there's some existing heuristic for what clang tools do, but generally I find it to either be something that the user interfaces in, or something that clang uses when it's building job actions. This is the latter.

https://github.com/llvm/llvm-project/pull/112245