[clang] [Clang] Propagate elide safe context through [[clang::coro_await_elidable_argument]] (PR #108474)

[Adrian Vogelsgesang via cfe-commits]

https://github.com/vogelsgesang commented:

Looks good to me, but at the same time: I am not experienced in the clang-frontend, so please wait for an approval of a more experienced clang-frontend contributor

https://github.com/llvm/llvm-project/pull/108474