[clang] [Clang] Add C++11/C23-style spellings for Swift import attributes (PR #183484)

[Tshaka Lekholoane via cfe-commits]

tshakalekholoane wrote:

Gentle ping -- just following up on my previous comment. The PR has passing tests and a release note. Happy to make any final adjustments (e.g. namespace) if needed.

https://github.com/llvm/llvm-project/pull/183484