dirstate-v2: Replace the 32-bit `mode` field with two bits
Previously we stored the entire value from `stat_result.st_mode`,
like dirstate-v1 does. However only the executable permission
and type of file (only symbolic links and normal files are supported)
are relevant to Mecurial.
So replace this field with two bits in the existing bitfield byte.
For now the unused space is left as padding, as it will be used
for something else soon.
Differential Revision: https://phab.mercurial-scm.org/D11635
Mercurial
=========
Mercurial is a fast, easy to use, distributed revision control tool
for software developers.
Basic install::
$ make # see install targets
$ make install # do a system-wide install
$ hg debuginstall # sanity-check setup
$ hg # see help
Running without installing::
$ make local # build for inplace usage
$ ./hg --version # should show the latest version
See https://mercurial-scm.org/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.
Notes for packagers
===================
Mercurial ships a copy of the python-zstandard sources. This is used to
provide support for zstd compression and decompression functionality. The
module is not intended to be replaced by the plain python-zstandard nor
is it intended to use a system zstd library. Patches can result in hard
to diagnose errors and are explicitly discouraged as unsupported
configuration.