Provide `list-immutable' in `mzscheme' compatibility module.
Provide `list-immutable' in `mzscheme' compatibility module.

svn: r8842

mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket