[clang] [SYCL] Basic code generation for SYCL kernel caller offload entry point functions. (PR #133030)

[Erich Keane via cfe-commits]

https://github.com/erichkeane requested changes to this pull request.

See comment re:auto: our lead maintainer's interpretation of our `auto` rules requires that we not use `auto` in this situation.   @AaronBallman for attention.

https://github.com/llvm/llvm-project/pull/133030