[clang] [clang] Substitute alias templates from correct context (PR #74335)

[Erich Keane via cfe-commits]

erichkeane wrote:

> This started to give errors to code previously considere valid with "out-of-line definition of X differs from that in". Don't have a repro yet.

Please provide one as soon as you can! In the meantime, we should probably revert @Fznamznon 

https://github.com/llvm/llvm-project/pull/74335