Prefer splitting argument after list start if before a tuple.

Without this, the arguments in the following will all be placed on
individual lines after reformatting:

    self._xxxxxxxx(aaaaaa, bbbbbbbbb, cccccccccccccccccc,
                   [('mmmmmmmmmm', self.yyyyyyyyyy.zzzzzzz/_DDDDD)], eee, 'ff')