Make sure we containerize arrays in @a <<+>> 0
Make sure we containerize arrays in @a <<+>> 0

Arrays were created, but without containers.  Fixes R#2840.  This **also**
fixes the case where the original array was typed: the type *and* its
associated descriptor are cloned.

tbrowder/rakudo,salortiz/rakudo,tony-o/rakudo,Gnouc/rakudo,nbrown/rakudo,rakudo/rakudo,labster/rakudo,nbrown/rakudo,MasterDuke17/rakudo,tbrowder/rakudo,rakudo/rakudo,salortiz/rakudo,tony-o/rakudo,tbrowder/rakudo,softmoth/rakudo,tbrowder/rakudo,labster/rakudo,MasterDuke17/rakudo,Gnouc/rakudo,MasterDuke17/rakudo,Gnouc/rakudo,Gnouc/rakudo,softmoth/rakudo,tony-o/rakudo,tbrowder/rakudo,nbrown/rakudo,salortiz/rakudo,labster/rakudo,Gnouc/rakudo,tony-o/rakudo,labster/rakudo,rakudo/rakudo,softmoth/rakudo,MasterDuke17/rakudo,labster/rakudo,tbrowder/rakudo,MasterDuke17/rakudo,nbrown/rakudo,salortiz/rakudo,nbrown/rakudo,rakudo/rakudo,rakudo/rakudo,Gnouc/rakudo,MasterDuke17/rakudo,softmoth/rakudo,labster/rakudo,salortiz/rakudo,softmoth/rakudo,tony-o/rakudo,nbrown/rakudo,salortiz/rakudo,tony-o/rakudo,rakudo/rakudo