Use node instead of ast for placeholder AST name
Use node instead of ast for placeholder AST name

Zoffix suggested this is more consistent with the Rakudo codebase

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