Frog allows dynamically adding methods to lists #1054
Description
The following code is not supposed to work, but the Frog compiler allows it and happily prints "hest". The A class is just there to silence a warning about bar() not being defined anywhere:
class A {
bar() { }
}
main() {
var a = [];
a["proto"]["bar$0"] = () { print('hest'); };
a.bar();
}