[clang] [Clang][Sema] Fix crash when MS dependent base class lookup occurs in an incomplete context (PR #83024)

[Erich Keane via cfe-commits]

https://github.com/erichkeane commented:

Needs a release note if this exists in a previous release.  Also, do you have a bug report here?

https://github.com/llvm/llvm-project/pull/83024