kill-perl6-proc.p6

my $proc = Proc::Async.new('perl6', '-e', 'warn "end"');                                                                                              
my $promise = $proc.start;                                                                                                                            
                                                                                                                                                      
$proc.kill;                                                                                                                                           
await Promise.allof($promise, Promise.in(0).then: { "hello".say; });                                                                                  
$promise.status.say;