Make sure "my ($a,$b)" does not have any runtime effect
Make sure "my ($a,$b)" does not have any runtime effect

Before this change, it would actually create a List each time the
scope with the definition was entered.  This does *not* take care
of the case where the variables are initialized.  This a different
can of beans.  jnthn++ for suggesting the code.

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