[SYCL] Add option forwarding from clang-linker-wrapper tool to clang-sycl-linker

[srividya-sundaram]

This is the first patch in a series that moves SYCL device code linking logic from clang-linker-wrapper into the clang-sycl-linker tool.
I’m continuing the work from where Yixing left off.

At the moment, the tests only verify that the options are forwarded to clang-linker-wrapper.
Tests validating clang-sycl-linker invocations will be added in subsequent PRs.

Added infrastructure from PR 21692 + tests for option forwarding.

[YuriPlyakhin]

I think this clean up should be submitted upstream. But before it is submitted upstream, I think we need to submit to upstream importing of device libraries in code-gen stage, similar to what we did in downstream.

Otherwise, functionality between community clang-sycl-linker and downstream clang-sycl-linker diverges a lot and it will be incrementally more and more difficult to maintain 2 variants of code.

[srividya-sundaram]

So,

1. Submit PR21672 upstream.
2. Submit --device-libs and --library-path cleanup upstream.

Is this correct understanding?
If yes, I can work on # 1 and # 2 submissions to upstream, and we can split this PR to have just the option forwarding + test changes and add the device libs cleanup after the upstream patches land.
WDYT?

[YuriPlyakhin]

Yes, that sounds correct to me. I don't know how 1. would look like in upstream (unlikely can be submitted as-is), since it seems there might be some functionality missing yet or code is different, but it would be the best way to move forward in my opinion.

[maksimsab]

More general comment.
I see that your PR targets 2 independent goals:

• Add option forwarding
• Remove deprecated device library options

In cases like that the suggested approach is:

The patch should:
* be an isolated change. Independent changes should be submitted as separate patches as this makes reviewing easier.

https://llvm.org/docs/Contributing.html#how-to-submit-a-patch

Please, use this approach in your patches.

[YuriPlyakhin]

could you please update title?