Go to Definition on Private Symbols

It's a not wholly uncommon occurrence for me to import or otherwise use something that's private within my own code and it always feels clunky to have to manually go to the symbol because Go To Definition doesn't work on private symbols.

Here's a minimum example:

fn main() {
    public_module::accidentally_private;
}

pub mod public_module {
    fn accidentally_private() {}
}

If you try to use Go to Definition on public_module::accidentally_private you're unable to, despite the fact that rustc itself points out the line number. It's not a huge deal, it'd just be nice to have as an improvement.

I'd be willing to submit a PR for this but I'd appreciate first knowing if this is a tenable idea as well as a rough direction, e.g. where Go to Definition happens and possibly how to look up private symbols if that's tricky.

Start by tracing the Go to Definition entry point in rust-analyzer and reproduce the private-symbol example from the issue. Determine how the declaration is resolved when rustc reports a visibility error, then add a regression test showing that Go to Definition reaches the private function declaration.