Able to define the same function twice

[AjaniBilby]

The tests to ensure function collisions always yield false for files and classes

[AjaniBilby]

The sample below will compile, and the resulting output will be world. This should not compile and instead should throw an error

fn main():int {
  println("Hello");
  return 0;
}
fn main():int {
  println("World");
  return 0;
}