remove dead code

Author: swannodette

src/main/cljs/cljs/core.cljs

@@ -8773,16 +8773,13 @@ reduces them without incurring seq initialization"
   [obj writer opts]
   (cond
     (nil? obj) (-write writer "nil")
-    (undefined? obj) (-write writer "#<undefined>")
     :else
     (do
       (when (print-meta? opts obj)
         (-write writer "^")
         (pr-writer (meta obj) writer opts)
         (-write writer " "))
       (cond
-        (nil? obj) (-write writer "nil")
-
         ;; handle CLJS ctors
         ^boolean (.-cljs$lang$type obj)
         (.cljs$lang$ctorPrWriter obj obj writer opts)