dirstate: same logic as what we did for `_drop` This is part of the dirstatemap so let the dirstatemap deal with it. Differential Revision: https://phab.mercurial-scm.org/D11423

dirstate: use `tracked` property in `_addpath` It is semantically better. Differential Revision: https://phab.mercurial-scm.org/D11422

rust: Update the memmap2 crate to version 0.4.0 This version: * Optionally implements the `StableDeref` trait, removing the need for a wrapper type doing that * Adds support for mapping empty files, which can routinely happen for dirstate-v2 data files. This was a cause of some failing tests when running with `run-tests.py --rhg --extra-config-opt rhg.status=1` Differential Revision: https://phab.mercurial-scm.org/D11446

dirstate: fix compilation warnings in `dirstate_item_set_possibly_dirty()` Since https://phab.mercurial-scm.org/D11387 (i.e. the same patch as mentioned in my previous patch), Clang has also started warning about `dirstate_item_set_possibly_dirty()` missing an explicit return, and about its use of the result of an assignment as a condition without using parentheses. This patch fixes that. Differential Revision: https://phab.mercurial-scm.org/D11445

dirstate: make dirstate flags char be unsigned Since https://phab.mercurial-scm.org/D11387, `CC='clang -Werror' make local` has started failing like this: ``` mercurial/cext/util.h:41:50: error: implicit conversion from 'int' to 'char' changes value from 128 to -128 [-Werror,-Wconstant-conversion] static const char dirstate_flag_rust_special = 1 << 7; ~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~^~~~ ``` This patch fixes that by making the flags be an unsigned char. That also matches the `bool` typedef we have in `util.h`, which seems good since many of the `dirstate_item_c_*()` functions return a `bool`. Differential Revision: https://phab.mercurial-scm.org/D11444

dirstate: introduce a `set_clean` method on dirstate's map and items This method is the "reverse" of "set possibly dirty", and can be used to more accurately other call that the dirstate was making. It is currently heavily influenced by its origin. Differential Revision: https://phab.mercurial-scm.org/D11421

dirstate: extract the logic to check file/dirname collision when adding a file Differential Revision: https://phab.mercurial-scm.org/D11420