FileInput.readLine() fails if last line is empty

The following code fails on all sys targets with an EOF exception, but shouldn't because before invoking readLine the EOF status is tested.

``` haxe
class Test {
static function main() {
sys.io.File.saveContent("test.txt", "line1\nline2\n");
var is = sys.io.File.read("test.txt", false);
while (!is.eof()) {
trace(is.readLine());
}
is.close();
}
}
```

The example works if

``` haxe
sys.io.File.saveContent("test.txt", "line1\nline2\n");
```

is replaced by

``` haxe
sys.io.File.saveContent("test.txt", "line1\nline2");
```