Fix stray \
Fix stray \

Apparently we don't test assigning to a buf with a native integer index :-(
Spotted while playing with sieve of erastothenes.

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