[clang-tools-extra] [clang-tidy] Add support for struct initialization in `bugprone-argument-comment` (PR #171757)

[Baranov Victor via cfe-commits]

vbvictor wrote:

> This is not a very small PR so I think it would be easier to review commit-by-commit.

For me, it's hard to review per-commit in github UI.
I'd more like to first have a couple of NFC refactor PRs that we can accept easily, and then have a final functional PR.

https://github.com/llvm/llvm-project/pull/171757