typing: add some trivial type hints to `mercurial/match.py`
These were new methods since hg
3dbc7b1ecaba, but surprisingly pytype couldn't
figure them out.
#require test-repo jshint hg10
$ . "$TESTDIR/helpers-testrepo.sh"
run jshint on all tracked files ending in .js except vendored dependencies
$ cd "`dirname "$TESTDIR"`"
$ testrepohg locate 'set:**.js' \
> 2>/dev/null \
> | xargs jshint