Compile-time debugging

* module/language/cps/compile-rtl.scm:
* module/language/cps/contification.scm: Add some compile-time
  printouts.  Will be removed later.

module/language/cps/compile-rtl.scm

@@ -50,7 +50,9 @@
 (define (optimize exp opts)
   (define (run-pass exp pass kw default)
     (if (kw-arg-ref opts kw default)
-        (pass exp)
+        (begin
+          (pk 'OPTIMIZING kw)
+          (pass exp))
         exp))
 
   ;; Calls to source-to-source optimization passes go here.
@@ -433,11 +435,13 @@
        (emit-end-program asm)))))
 
 (define (compile-rtl exp env opts)
+  (pk 'COMPILING)
   (let* ((exp (fix-arities exp))
          (exp (optimize exp opts))
          (exp (convert-closures exp))
          (exp (reify-primitives exp))
          (asm (make-assembler)))
+    (pk 'CODEGEN)
     (visit-funs (lambda (fun)
                   (compile-fun fun asm))
                 exp)