I added a test case which does not compile today, and required changes on
privacy's side of things to get right. Additionally, this moves a good bit of
logic which did not belong in reachability into privacy.
All of reachability should solely be responsible for determining what the
reachable surface area of a crate is given the exported surface area (where the
exported surface area is that which is usable by external crates).
Privacy will now correctly figure out what's exported by deeply looking
through reexports. Previously if a module were reexported under another name,
nothing in the module would actually get exported in the executable. I also
consolidated the phases of privacy to be clearer about what's an input to what.
The privacy checking pass no longer uses the notion of an "all public" path, and
the embargo visitor is no longer an input to the checking pass.
Currently the embargo visitor is built as a saturating analysis because it's
unknown what portions of the AST are going to get re-exported.
Previously, the `exported_items` set created by the privacy pass was
incomplete. Specifically, it did not include items that had been defined
at a private path but then `pub use`d at a public path. This commit
finds all crate exports during the privacy pass. Consequently, some code
in the reachable pass and in rustdoc is no longer necessary. This commit
then removes the separate `MissingDocLintVisitor` lint pass, opting to
check missing_doc lint in the same pass as the other lint checkers using
the visibility result computed by the privacy pass.
Fixes#9777.
