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
# repoviewutil.py - constaints data relevant to repoview.py and other module
#
# Copyright 2012 Pierre-Yves David <pierre-yves.david@ens-lyon.org>
# Logilab SA <contact@logilab.fr>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
### Nearest subset relation
# Nearest subset of filter X is a filter Y so that:
# * Y is included in X,
# * X - Y is as small as possible.
# This create and ordering used for branchmap purpose.
# the ordering may be partial
subsettable = {
None: b'visible',
b'visible-hidden': b'visible',
b'visible': b'served',
b'served.hidden': b'served',
b'served': b'immutable',
b'immutable': b'base',
}