test for optimizer lifting with unused rest arg

svn: r5793

collects/tests/mzscheme/optimize.ss

@@ -459,6 +459,16 @@
   (set! i 10))
 (err/rt-test (dynamic-require 'bad-order #f))
 
+;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+;; Check lifting of a function with only an unused rest arg:
+
+(test 1 'continue
+      (let/ec foo
+        (let ([continue (lambda extras
+                          (foo 1))])
+          (+ 1 (continue)))))
+
 ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; call-with-values optimization