dirstate: move opendirstatefile to dirstatemap
As part of moving the dirstate storage logic to another class, let's move
opendirstatefile to dirstatemap. This will allow extensions to replace the
pending abstraction.
Future patches will move the consumers of _opendirstatefile into dirstatemap as
well.
Differential Revision: https://phab.mercurial-scm.org/D757
syntax: glob
*.elc
*.tmp
*.orig
*.rej
*~
*.mergebackup
*.o
*.so
*.dll
*.exe
*.pyd
*.pyc
*.pyo
*$py.class
*.swp
*.prof
*.zip
\#*\#
.\#*
tests/.coverage*
tests/.testtimes*
tests/.hypothesis
tests/hypothesis-generated
tests/annotated
tests/*.err
tests/htmlcov
build
contrib/chg/chg
contrib/hgsh/hgsh
contrib/vagrant/.vagrant
contrib/docker/debian-*
contrib/docker/ubuntu-*
dist
packages
doc/common.txt
doc/*.[0-9]
doc/*.[0-9].txt
doc/*.[0-9].gendoc.txt
doc/*.[0-9].{x,ht}ml
MANIFEST
MANIFEST.in
patches
mercurial/__modulepolicy__.py
mercurial/__version__.py
mercurial/hgpythonlib.h
mercurial.egg-info
.DS_Store
tags
cscope.*
.idea/*
.asv/*
i18n/hg.pot
locale/*/LC_MESSAGES/hg.mo
hgext/__index__.py
# Generated wheels
wheelhouse/
syntax: regexp
^\.pc/
^\.(pydev)?project
# hackable windows distribution additions
^hg-python
^hg.py$