[clang] [clang] Implement instantiation context note for checking template parameters (PR #126088)

[Matheus Izvekov via cfe-commits]

mizvekov wrote:

> @mizvekov are you still working on that? Thanks

I figured out what was wrong with the original patch but never went back to fix it, it's still on my backlog.

https://github.com/llvm/llvm-project/pull/126088