[clang] Mark an ObjCIvarDecl as invalid if its type contains errors (PR #68001)

[Shafik Yaghmour via cfe-commits]

shafik wrote:

The PR description could have used more details. Was this fixing a crash bug, a conformance issue, lack of diagnostic etc What is the new behavior would also be helpful.

Was there a bug report linked to this fix? Is so that should be linked in the description.

If we are fixing a bug we should also include an entry in the Release notes.

https://github.com/llvm/llvm-project/pull/68001