[clang] [Clang][Sema] Always use latest redeclaration of primary template (PR #114258)

[Felipe de Azevedo Piovezan via cfe-commits]

felipepiovezan wrote:

> > @felipepiovezan I tested without this patch applied and was still seeing crashes... could you perhaps see if https://github.com/sdkrystian/llvm-project/tree/reapply-use-latest-primary fixes the regression?
> 
> Let me give it a try now!

Yup, that fixes the issue. I've also confirmed that reverting the fix brings back the crash!

It is weird that you were unable to repro this 🤔 Were you perhaps not building libcxx at the same time?

https://github.com/llvm/llvm-project/pull/114258