incorrect line number reported for index out of range error

If you run:

```
function foo()
    x = ones(10)
    print("first access\n")
    x[1]
    print("second access\n")
    x[20]
end
foo()
```

the result is

```
first access
second access
in foo: arrayref: index out of range
 in foo at none:4
```

Note the line number is incorrect. As in #900, this isn't helpful when trying to debug :)
