rust: introduce SIZE_FROM_OTHER_PARENT constant This will clarify what `-2` meant in the codebase. This change also merged imports in affected files for cleanup. Differential Revision: https://phab.mercurial-scm.org/D7301

rust-status: refactor dispatch case for normal files This should make the code easier to read and more idiomatic. Differential Revision: https://phab.mercurial-scm.org/D7300

rust-status: return a ParallelIterator instead of a Vec from stat_dmap_entries This allows the caller function to choose when and how the iteration and/or collection happens. This change also cleans up the now unused `filter_map`. Differential Revision: https://phab.mercurial-scm.org/D7299

rust-status: improve status performance This change does more things in the parallel loop, refactors the file-level logic into two functions for added clarity. This bit of Rust code takes 55ms to execute on a repo where the stat'ing part of Valentin's fast path takes 40ms. While the code differs a bit and it's hard to get an exact measurement of how much of a performance impact it has, I can be fairly certain that this implementation is *at worse* twice as slow. Differential Revision: https://phab.mercurial-scm.org/D7254

bookmarks: accept explicit -r 'wdir()' when adding new bookmarks (issue6218) Even though the bookmark semantics can't be fully encoded to the virtual working changeset idea, the active bookmark can be considered a bookmark of the working revision. Before, 'tgt' was None, and changes=[(bm, None)] means deleting a bookmark named 'bm'.

bookmarks: use changectx instead of remembering hex of hidden revision It should be better to not depend on the ctx variable which was assigned conditionally.