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

[Tom Honermann via cfe-commits]

tahonermann wrote:

> I can't find our conversation again and firefox crashed before I could submit, but PLEASE make sure the mangling tests cover the examples we put together.

I absolutely will.

> ALSO, we don't always mangle the types of lambdas, we sometimes do $_0 and $_1 (source of another bug) for ones without external linkage.

Yup. That gets us into the fun topic of what it means for a symbol with internal linkage to be accessible from both a host and device TU. Fortunately not something we need to address right now!

Thanks for the review.

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