import-checker: allow symbol imports from typing module As we add typing annotations, we'll want to use a lot of symbols from the `typing` module. Typing `typing` all the time will be annoying. Let's allow symbol imports from this module. While I was here, I changed some comments from "whitelist" to "allow list" as the former is non-inclusive terminology. Differential Revision: https://phab.mercurial-scm.org/D12365

#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