[clang] [llvm] [Driver][SYCL] Add initial SYCL offload compilation support (PR #107493)

[Tom Honermann via llvm-commits]

https://github.com/tahonermann commented:

I was late to re-review these changes before they landed. However, since the changes have been reverted, I took the opportunity to review again and I have a number of concerns that I would like to see addressed before these changes land again. Though I've noted the issues in this PR, I expect a new PR will be needed to address them and re-land the revised patch.

https://github.com/llvm/llvm-project/pull/107493