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

[Erich Keane via cfe-commits]

erichkeane wrote:

> > That said, if you get to be somewhat more sure that this is the patch that caused it, feel free to revert and @sdkrystian will look at it more closely tomorrow.
> 
> I'm going to revert it for the time being to unblock the bots

Sorry, was off at lunch :)  That seems reasonable/appropriate.

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