dirstate-item: move the C implementation to the same logic Now that we know were we are going, we can update the C implementation. Differential Revision: https://phab.mercurial-scm.org/D11387

dirstate-item: introduce low level C function Since a lot of logic is about to change, we need to isolate it into bits that are easy reusable in the rest of the C code. Especially we need to split the part that do the pure logic from the part that do the Python wrapping. Differential Revision: https://phab.mercurial-scm.org/D11386

dirstate-item: factor some code in the C implementation We have both `dirstate_item_from_v1_meth`, a class method, and `dirstate_item_from_v1_data`, a function taking low level C argument. Lets implement the former with the later. Differential Revision: https://phab.mercurial-scm.org/D11385

dirstate-item: `dirstate_item_from_v1_data` replaces make_dirstate_item For different format, we will need multiple capsule anyways. Differential Revision: https://phab.mercurial-scm.org/D11384

pathutil: replace the `skip` argument of `dirs` with a boolean It is ever only used for `r` file. So we make it a boolean this will give use more versatility later as we will stop storing the state explicitly. Differential Revision: https://phab.mercurial-scm.org/D11383

dirstate: clarify the message in nonnormal checking The previous message was quite verbose and hard to understand. The new one should be friendlier. Differential Revision: https://phab.mercurial-scm.org/D11382

merge: with stable