make comprehensions use (top +) instead of +

src/julia-syntax.scm

@@ -1556,7 +1556,7 @@
  `(block (= ,oneresult ,expr)
  (type_goto ,initlabl)
  (call (top setindex!) ,result ,oneresult ,ri)
- (+= ,ri 1))
+ (= ,ri (call (top +) ,ri 1)))
  `(for ,(car ranges)
  ,(construct-loops (cdr ranges)))))
 
@@ -1596,7 +1596,7 @@
  (define (construct-loops ranges rs)
  (if (null? ranges)
  `(block (call (top setindex!) ,result ,expr ,ri)
- (+= ,ri 1))
+ (= ,ri (call (top +) ,ri 1)))
  `(for (= ,(cadr (car ranges)) ,(car rs))
  ,(construct-loops (cdr ranges) (cdr rs)))))
 
@@ -1714,9 +1714,9 @@
  (if (null? ranges)
  (if (null? iters)
  `(block (call (top setindex!) ,result ,expr ,ri)
- (+= ,ri 1))
+ (= ,ri (call (top +) ,ri) 1))
  `(block (call (top setindex!) ,result (ref ,expr ,@(reverse iters)) ,ri)
- (+= ,ri 1)) )
+ (= ,ri (call (top +) ,ri 1))) )
  (if (eq? (car ranges) `:)
  (let ((i (gensy)))
  `(for (= ,i (: 1 (call (top size) ,oneresult ,oneresult-dim)))