Think I got it...

gistfile1.pl

my @q;
sub async(&f){
	push @q, $(gather {f({take $_})} )
}; 

sub yield {
	for @q -> $l {
		push @q, $l if $l.shift
	}
}

for <a b c> -> $x { 
	async { 
		say $x; 
		$^yield(5); 
		say "unyeilded $x";
	}
}


say "Made 3 asyncs";

yield();

say "Back to main";

yield();

say "Done";

./perl6 tgadsf.pl
Made 3 asyncs
a
b
c
Back to main
unyeilded a
unyeilded b
unyeilded c
Done