grammar: match subject can include starred expression

[isidentical]

E.g:

(.venv) (3.9.5) [  6:51ÖS ]  [ isidentical@msi:~ ]
 $ cat t.py                                                                                                   122ms
match x, *something:
    case _:
        pass
        
(.venv) (3.9.5) [  6:51ÖS ]  [ isidentical@msi:~ ]
 $ black -tpy310 --fast t.py                                                                                    2ms
error: cannot format t.py: Cannot parse: 1:6: match x, *something:
Oh no! 💥 💔 💥
1 file failed to reformat.
(.venv) (3.9.5) [  6:51ÖS ]  [ isidentical@msi:~ ]
 $ .venv310/bin/python -m ast t.py                                                                            135ms
Module(
   body=[
      Match(
         subject=Tuple(
            elts=[
               Name(id='x', ctx=Load()),
               Starred(
                  value=Name(id='something', ctx=Load()),
                  ctx=Load())],
            ctx=Load()),
         cases=[
            match_case(
               pattern=MatchAs(),
               body=[
                  Pass()])])],
   type_ignores=[])