Given the following program:

class S<T> { T t; }
class C { class I { }; }
class E extends S<C> {{
  t = new C();
  ((C) t).new I() { };
}};
public class X {
  public static void main(String[] args) { new E(); }
}

(the customer suggested workaround for https://bugs.openjdk.java.net/browse/JDK-8043741),
the compiler ends up creating an abstract syntax tree for class E whose textual representation
looks like:

class E extends S {
    
    E() {
        super();
    }
    {
        t = new C();
        new E$1(this, <*nullchk*>((C)(C)t));
    }
}

i.e. there is a compiler inserted redundant type cast operation.

While this is harmless (in fact this redundant cast does not make it to class files being trimmed
by Gen.visitTypeCast), this is best avoided.