Fix unsized field order

Author: nvzqz

example/mini_core_hello_world.rs

@@ -48,8 +48,8 @@ struct NoisyDrop {
 }
 
 struct NoisyDropUnsized {
-    text: str,
     inner: NoisyDropInner,
+    text: str,
 }
 
 struct NoisyDropInner;