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

[Matheus Izvekov via cfe-commits]

mizvekov wrote:

Correction, I was thinking of a different PR.

I did not test this PR on compile-time-tracker, as we didn't anticipate an impact.

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