[clang] [clang] Add test for CWG2091 "Deducing reference non-type template arguments" (PR #100765)

[Vlad Serebrennikov via cfe-commits]

Endilll wrote:

> [200](https://github.com/llvm/llvm-project/pull/97200) to land first, then update this PR with the output of `make_cxx_dr_status`.

This is done.

https://github.com/llvm/llvm-project/pull/100765