phases: provide a test and accessor for non-public phase roots This decouples users from the implementation details of the phasecache. Also document a historic artifact about the stored phaseroots. Differential Revision: https://phab.mercurial-scm.org/D8694

hg-core: define a `dirstate_status` `Operation` This is 3/3 in a series of patches to improve dirstate status' code. Following in the footsteps of a46e36b82461, we move the main status functionality to an `Operation`. This will most likely be subject to change in the future (what function signature, what parameters, etc., but we will see when `rhg` gets `hg status` support. Differential Revision: https://phab.mercurial-scm.org/D8663

rust-status: improve documentation and readability This patch is 2/3 in the series to improve the dirstate status code. It adds a number of common type aliases to add more obvious semantics to function signatures, improves/adds documentation where necessary and improves one or two patterns to be more idiomatic. Differential Revision: https://phab.mercurial-scm.org/D8662

rust-status: refactor status into a struct The code for `dirstate/status` has grown too large for comfort, this is the first of three patches that try to improve maintainability. In this patch, refactoring dirstate's status into a struct allows for slimming down function signatures drastically, keeping the mental (and maintenance) burden lower, since pretty much all of them shared a few common arguments. This had the pleasant side-effect of simplifying lifetimes a little. This has no observable impact on performance. The next patch will add/improve documentation and refactor some types. I tried to keep new code down to a minimum in this patch because it's already pretty big. Differential Revision: https://phab.mercurial-scm.org/D8661

tests: avoid "magic" nodeids in test-rebase-legacy.t This helps with readability. Differential Revision: https://phab.mercurial-scm.org/D8735

tests: avoid a "magic" nodeid in test-wireproto-command-lookup.t This helps with readability. Differential Revision: https://phab.mercurial-scm.org/D8734

run-tests: replace '#' with '-' in temp path of repos created for tests If we have multiple cases in a test, that leads us to a temp path of format "<temp-path>-<case1>#<case2>". This leads to hg.parseurl() parsing the path and take part after `#` as a branch name. I encountered this bug while adding support for share-safe case in next patch. Differential Revision: https://phab.mercurial-scm.org/D8647