Inlined cost calculation for loop unrolling

Would it be possible to calculate the cost of loop unrolling after inlining?

```hx
class Test {
static function main()
for (i in 0...3) {
switch 4 {
case 0: trace("0");
case 1: trace("1");
case 2: trace("2");
case 3: trace("3");
case 4: trace("4");
case 5: trace("5");
case 6: trace("6");
case 7: trace("7");
case 8: trace("8");
case 9: trace("9");
case 10: trace("10");
case 11: trace("11");
case 12: trace("12");
case 13: trace("13");
case 14: trace("14");
case 15: trace("15");
case 16: trace("16");
}
}
}
```
Generated output:
```js
// Generated by Haxe 4.0.0-rc.5+97d365b7f
(function ($global) { "use strict";
var Test = function() { };
Test.main = function() {
var _g = 0;
while(_g < 3) {
++_g;
console.log("root/program/Test.hx:9:","4");
}
};
Test.main();
})({});
```
http://try-haxe.mrcdk.com/#a09C5