[clang] [clang] Diagnose use of deprecated template alias (PR #97619)

[Matheus Izvekov via cfe-commits]

mizvekov wrote:

For reference, see https://reviews.llvm.org/D136533 for similar expansion of diagnostics for uses of declarations, and how that lead to trouble in MacOS land.

I'd suggest building libc++ on MacOS, to be sure this won't cause regressions and a future revert.

I have a MacOS machine now, so I should be able to try to revive that patch at some point as well.

https://github.com/llvm/llvm-project/pull/97619