[clang] [Clang][Sema] Revise the transformation of CTAD parameters of nested class templates (PR #91628)

[Younan Zhang via cfe-commits]

zyn0217 wrote:

I'm merging it now - if something breaks and I'm not in front of my computer, feel free to revert then.

https://github.com/llvm/llvm-project/pull/91628