[UR][SYCL] Implement USM prefetch from device to host in SYCL runtime and UR

[ianayl]

Add the ability to control USM prefetch direction (host-to-device, device-to-host) in the enqueue_function extension:

sycl::ext::oneapi::experimental {
    enum class prefetch_type { device, host };

    void prefetch(sycl::queue q, void* ptr, size_t numBytes,
                          prefetch_type type = prefetch_type::device);
    void prefetch(sycl::handler &h, void* ptr, size_t numBytes,
                          prefetch_type type = prefetch_type::device);
}

Note:

• There is a test failure regarding a new ABI symbol: In order to not break the ABI, I added a new handler function to represent prefetch from device-to-host. Despite the precommit failures, this should not be an ABI-breaking change and thus be okay to merge. I modified the ABI symbols tests as a part of this PR.

[steffenlarsen]

@ianayl - I think you forgot to push the changes relating to my comments. No biggie, but I unresolved them just to act as a reminder to get them pushed. 😉

Seems to just be my browser not updating, for some reason. Disregard this comment!

[steffenlarsen]

LGTM!

[ianayl]

Hi @intel/unified-runtime-reviewers, mind if I get a review? Thanks in advance!

[ianayl]

There is a UR precommit failure for CUDA: it is unrelated to the changes here.

The same test fails on latest commit of sycl as of 08/01/2025 as well, see UR CUDA precommit run from PR #19686: https://github.com/intel/llvm/actions/runs/16684666037/job/47231876973?pr=19686