tests themselves contain the expected result

tests/accept/run/titer2.nim

@@ -1,3 +1,7 @@
+discard """
+  file: "titer2.nim"
+  output: "123"
+"""
 # Try to break the transformation pass:
 iterator iterAndZero(a: var openArray[int]): int =
   for i in 0..len(a)-1:
@@ -8,3 +12,5 @@ var x = [[1, 2, 3], [4, 5, 6]]
 for y in iterAndZero(x[0]): write(stdout, $y)
 #OUT 123
 
+
+