[clang] [clang][AST] Hash `AttributedType`'s `Attr` by Arguments (PR #200961)

[Balázs Benics via cfe-commits]

steakhal wrote:

Thinking about this, I think we should mention this in the clang/docs/ReleaseNotes higlighting that there was a regression of 10%+ module size increase, potential slowdown in clang-X and now it's fixed and a link to the gh issue or pr.

https://github.com/llvm/llvm-project/pull/200961