[clang] [clang][SYCL] Add support for handling of special SYCL types (PR #210319)

[Mariya Podchishchaeva via cfe-commits]

Fznamznon wrote:

I'm not going to continue working on this PR but @elizabethandrews will, thanks! Closing since a new PR will be created.

https://github.com/llvm/llvm-project/pull/210319