[clang] [Clang][Sema] Account for types coming from template parameter when diagnosing mem initializer order issues (PR #201586)

[Yanzuo Liu via cfe-commits]

zwuis wrote:

I don't know whether #201379 is a correct approach but we should diagnose prior to template instantiations as much as possible.

https://github.com/llvm/llvm-project/pull/201586