[clang] [clang] Represent array refs as `TemplateArgument::Declaration` (PR #80050)

[Andrey Ali Khan Bolshakov via cfe-commits]

bolshakov-a wrote:

> Please do!

#80150. I don't know, maybe, some more actions should be done. I cannot add "release:backport" label, at least.

https://github.com/llvm/llvm-project/pull/80050