Loop "for" with range(from, to, step) doesn't work

Module std, function range, output is empty if from more than to:
```scala
for x : range(20, 9, -2) {
 println x
}
```
So too
```scala
for x : range(10, 1) {
 println x
}
```

This code work:
```scala
r= range(20, 9, -5)

for i : range(length(r)) {
    print r[i]
}

for i : range(4, 10, 2) {
  print i
}
```

