normal haxe/javascript class.__init__ output compared to custom haxe/javascript class.__init__ output

example.js

// normal haxe/javascript output for class.__init__ methods
{
	js.Lib.document = document;
	js.Lib.window = window;
	onerror = function(msg,url,line) {
		var f = js.Lib.onerror;
		if( f == null )
			return false;
		return f(msg,[url+":"+line]);
	}
}
{
	var hello = "sk";
	var i = 1;
}
// odd custom haxe/javascript output for class.__init__ methods
(function($this) {
	var $r;
	js.Lib.document = document;
	js.Lib.window = window;
	$r = onerror = function(msg,url,line) {
		var f = js.Lib.onerror;
		if( f == null )
			return false;
		return f(msg,[url+":"+line]);
	}
	return $r;
}(this));
(function($this) {
	var $r;
	var hello = "sk";
	$r = (function($this) {
		var $r;
		var i = 1;
		return $r;
	}($this));
	return $r;
}(this));