Six films to watch this week

Mid-life sex comedy ‘The Invite’ has an all-star ensemble; ‘Nirvanna the Band the Show the Movie’ is a lo-fi ‘Back to the Future’ for failed rockers; ‘Birds of War’ documents a love story shaped by war; ‘Supergirl’ brings attitude to the summer blockbuster; five stars for family drama ‘Blue Heron’; Jodie Foster turns French sleuth in ‘A Private Life’. Reviews by Danny Leigh