[clang] [clang] Report narrowing conversions with const references (PR #75332)

[Mariya Podchishchaeva via cfe-commits]

Fznamznon wrote:

> Looks like you got what I meant anyway, and we WERE just passionately agreeing with eachother :) LGTM.

Thanks!
Probably I was being a bit slow, lol

https://github.com/llvm/llvm-project/pull/75332