Context.defineType types TDStructure fields too eagerly

```haxe
class Macro {
public static function run() {
var def1 = macro class Def1 {
var def2:Def2;
}
var def2 = macro class Def2 {}

def1.kind = TDStructure; // comment this line to "fix"

haxe.macro.Context.defineType(def1);
trace('defined def1');
haxe.macro.Context.defineType(def2);
trace('defined def2');

}
}
```

Run it as init macro:
```hxml
--macro Macro.run()
```

Expect to trace "defined def1" and "defined def2" but actually prints "Type not found : Def2"