rust: Move "lookup" a.k.a. "unsure" paths into `DirstateStatus` struct Instead of having `status()` returning a tuple of those paths and `DirstateStatus`. Differential Revision: https://phab.mercurial-scm.org/D10494

rust: Remove DirstateMap::file_fold_map This was a HashMap constructed on demand and then cached in the DirstateMap struct to avoid reconstructing at the next access. However the only use is in Python bindings converting it to a PyDict. That method in turn is wrapped in a @cachedproperty in Python code. This was two redudant layers of caching. This changeset removes the Rust-level one to keep the Python dict cache, and have bindings create a PyDict by iterating. Differential Revision: https://phab.mercurial-scm.org/D10493

dirstate-tree: Add "non normal" and "from other parent" sets Unlike the other DirstateMap implementation, these sets are not materialized separately in memory. Instead we traverse the main tree. Differential Revision: https://phab.mercurial-scm.org/D10492

dirstate-tree: Add add_file, remove_file, and drop_file Again, various counters need to be kept up to date. Differential Revision: https://phab.mercurial-scm.org/D10491

dirstate-tree: Add has_dir and has_tracked_dir A node without a `DirstateMap` entry represents a directory. Only some values of `EntryState` represent tracked files. A directory is considered "tracked" if it contains any descendant file that is tracked. To avoid a sub-tree traversal in `has_tracked_dir` we add a counter for this. A boolean flag would become insufficent when we implement remove_file and drop_file. `add_file_node` is more general than needed here, in anticipation of adding the `add_file` and `remove_file` methods. Differential Revision: https://phab.mercurial-scm.org/D10490

dirstate-tree: Add clear_ambiguous_times in the new DirstateMap Also drive-by refactor it in the other DirstateMap Differential Revision: https://phab.mercurial-scm.org/D10489