tests/test-check-clang-format.t

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 clang-format test-repo

  $ . "$TESTDIR/helpers-testrepo.sh"

  $ cd "$TESTDIR"/..
  $ for f in `testrepohg files 'set:(**.c or **.cc or **.h) and not "listfile:contrib/clang-format-ignorelist"'` ; do
  >   clang-format --style file $f > $f.formatted
  >   cmp $f $f.formatted || diff -u $f $f.formatted
  >   rm $f.formatted
  > done