dirstate: explicitely deal with the `added` case in `_addpath` This special case is now directly handled, this clarify the possible value for the other options. Differential Revision: https://phab.mercurial-scm.org/D10933

dirstate: add an explicit `possibly_dirty` parameter to `_addpath` This lets says what we mean instead of using magic value. The lower level can then decide how to express that. Differential Revision: https://phab.mercurial-scm.org/D10932

dirstate: add an explicit `from_p2` parameter to `_addpath` This lets says what we mean instead of using magic value. The lower level can then decide how to express that. Differential Revision: https://phab.mercurial-scm.org/D10931

dirstate: add default value to _addpath We want to remove the magic value usage from the higher level, so lets stop passing them explicitely when possible. Differential Revision: https://phab.mercurial-scm.org/D10930

dirstate: move the _rangemask filtering closer to its storage The goal is to get ready to move these kind of processing at a lower level. We start with move move _rangemask filtering close to where it is sent to the lower level to make the future move trivial. Differential Revision: https://phab.mercurial-scm.org/D10929

dirstate: introduce a symbolic constant for the AMBIGUOUS_TIME marker This is going to be clearer and easier to track than -1. Ultimately I would like to get ride of this special value everywhere but in the lower level, however we need to clarify the API first. This changeset is part of such clarification. Differential Revision: https://phab.mercurial-scm.org/D10928