shelve: do not add the dirstate backup to the transaction
Otherwise the transaction will properly clean up its mess on abort… deleting the
backup in the process.
This break with dirstate-v2 that has more file than just the dirstate. The
dirstate itself is full of various exception and is "fine" when using
dirstate-v1.
#require black test-repo
Black needs the real USERPROFILE in order to run on Windows
#if msys
$ USERPROFILE="$REALUSERPROFILE"
$ export USERPROFILE
#endif
$ cd $RUNTESTDIR/..
$ black --check --diff `hg files 'set:(**.py + grep("^#!.*python")) - mercurial/thirdparty/**'`