Closure clone per supply/react, not per whenever
Closure clone per supply/react, not per whenever

Saves some work for supply/react blocks that have multiple whenever
blocks inside of them. Also sprinkle some comments explaining what's
going on.

awwaiid/rakudo,usev6/rakudo,rakudo/rakudo,tbrowder/rakudo,tony-o/rakudo,tony-o/rakudo,lucasbuchala/rakudo,nbrown/rakudo,awwaiid/rakudo,jonathanstowe/rakudo,labster/rakudo,raydiak/rakudo,labster/rakudo,Gnouc/rakudo,softmoth/rakudo,Gnouc/rakudo,tbrowder/rakudo,labster/rakudo,lucasbuchala/rakudo,rakudo/rakudo,tbrowder/rakudo,Gnouc/rakudo,salortiz/rakudo,MasterDuke17/rakudo,labster/rakudo,jonathanstowe/rakudo,usev6/rakudo,tbrowder/rakudo,rakudo/rakudo,rakudo/rakudo,softmoth/rakudo,jonathanstowe/rakudo,salortiz/rakudo,salortiz/rakudo,Gnouc/rakudo,salortiz/rakudo,softmoth/rakudo,rakudo/rakudo,tbrowder/rakudo,jonathanstowe/rakudo,softmoth/rakudo,usev6/rakudo,rakudo/rakudo,salortiz/rakudo,awwaiid/rakudo,tony-o/rakudo,usev6/rakudo,MasterDuke17/rakudo,tbrowder/rakudo,lucasbuchala/rakudo,tony-o/rakudo,Gnouc/rakudo,jonathanstowe/rakudo,nbrown/rakudo,lucasbuchala/rakudo,nbrown/rakudo,Gnouc/rakudo,labster/rakudo,raydiak/rakudo,tony-o/rakudo,awwaiid/rakudo,MasterDuke17/rakudo,labster/rakudo,usev6/rakudo,MasterDuke17/rakudo,raydiak/rakudo,MasterDuke17/rakudo,MasterDuke17/rakudo,salortiz/rakudo,lucasbuchala/rakudo,awwaiid/rakudo,nbrown/rakudo,tony-o/rakudo,nbrown/rakudo,raydiak/rakudo,softmoth/rakudo,nbrown/rakudo