For-each statement not yet supported in code generator

[wegendt-bosch]

One of the first things I wanted to try is:

every button_one.pressed {

	let myList = [1, 2, 3];
	for (var i in myList) {
		print(`${i}`);
	}
}

But it just gives me an unsatisfying:

// ERROR: for-each statements are not supported yet

In the generated source code.

We should either fix this in the generator (how complex is this?), or prevent the user of using that statement (at least a warning).