Typedefs doesn't give hint about the type of the field on runtime.

Code below will do an `Int` multiplication and overflow even though typedef suggests to use the `floatField` field as a type of `Float`.

```haxe
typedef TestDef = {
@:optional var floatField:Float;
}
typedef TestDef2 = {
@:optional var multiplied:Float;
}

class Test {
static function main() {
if (testOverflow()) trace("testOverflow passed");
else trace("testOverflow failed");
}

static function testOverflow():Bool {
trace("starting testOverflow");

var testDef:TestDef = { floatField: 50000000 };

var def:TestDef2 = {
multiplied: testDef.floatField * 400
};

trace('result is: ${def.multiplied}');
return def.multiplied > 0;
}
}
```