[clang] [Clang][Sema] fix crash of attribute transform (PR #78088)

[Qizhi Hu via cfe-commits]

jcsxky wrote:

> There seems to be an issue with the rebasing of the PR. As we branch clang 18, the new changelog (for 19) being empty is expected

I try to merge this PR and found `ReleaseNotes.rst` is changed because of clang-19 initialize. I don't know where should I add the release note.

https://github.com/llvm/llvm-project/pull/78088