dirstate: drop duplicated check This is covered by the `@requires_parents_change` decorator that this function use. Differential Revision: https://phab.mercurial-scm.org/D11125

dirstate: add a `set_possibly_dirty` in `fakedirstatewritetime` Differential Revision: https://phab.mercurial-scm.org/D11122

dirstatemap: use `set_possibly_dirty` in `clearambiguoustimes` lets put this new method to use Differential Revision: https://phab.mercurial-scm.org/D11121

dirstate-item: use `set_possibly_dirty` in `pure.pack_dirstate` Lets make use of the new function. Differential Revision: https://phab.mercurial-scm.org/D11120

dirstate-item: add a `set_possibly_dirty` method See inline documentation for details. The pushes the AMBIGUOUS_TIME implementation further down the line within the DirstateItem only. When this cleanup is done we will be able to stop using this representation internally. Differential Revision: https://phab.mercurial-scm.org/D11119

dirstate-item: add a `from_v1_data` constructor This class method is dedicated to building a DirstateItem from the data available in the "dirstate-v1" format. Since that format is frozen, this constructor will never change (unlike the `__init__` one). Differential Revision: https://phab.mercurial-scm.org/D11118

dirstate-item: use an explicit __init__ function instead of the attrs one For now, this is not doing anything special, however we plan to make it different in the future. So we start simple. Differential Revision: https://phab.mercurial-scm.org/D11117