[clang] [Clang] Fix isWeakImported() to traverse redeclaration chain for avai… (PR #181482)

[Victor Chernyakin via cfe-commits]

https://github.com/localspook commented:

- Did you use AI to write the PR description and/or the code? If so, you need to disclose it: https://llvm.org/docs/AIToolPolicy.html

- Please add "Fixes #181298 " to the PR message so github will autoclose that issue if this PR is merged (it isn't enough to just write "Related to #181298" in a separate comment)

I've added some other people, since I'm not super qualified to review this area of the code. With that being said...



https://github.com/llvm/llvm-project/pull/181482