schemify: fix problem with inlining

Recently added support for inlining functions with a "rest" arg
exposed a problem in constructing an inlining environment.

racket/src/schemify/inline.rkt

@@ -99,7 +99,7 @@
                (loop (wrap-cdr args)))]
         [else
          (define u (unwrap args))
-         (list (cons u (gensym u)))])))
+         (cons (cons u (gensym u)) base-env)])))
   (values (let loop ([args args] [env env])
             (cond
               [(wrap-null? args) '()]