[clang] [WIP] Implement `-dump-deserialized-declaration-ranges` flag. (PR #133910)

[Ilya Biryukov via cfe-commits]

https://github.com/ilya-biryukov commented:

Thanks, the implementation mostly looks good. I've left a lot of comments, but they are mostly NITs. One major thing that we need to change is the way we test this, see the comment about relying on `jq`.

Another thought that crossed my mind is that we are actually heavily optimizing for minimization, but use a name that creates an impression we might care about something else. I don't have great ideas there, but maybe `-dump-minimization-hints`  would be appropriate? Any thoughts on this?

It would be great to link to the code consuming those hints in `cvise` too to add some context on why we are doing this.

https://github.com/llvm/llvm-project/pull/133910