Recent versions of javac no longer emit a checkcast in the body of the lambda expression below, which seems like a regression.

This was introduced by the fix for JDK-8203338:
http://hg.openjdk.java.net/jdk/jdk/rev/e0eca40cd514
https://bugs.openjdk.java.net/browse/JDK-8203338

```
abstract class T {

  interface I<X> {
    X d();
  }

  abstract <X> I<X> c();

  void f() {
    Runnable r = () -> this.<Long>c().d();
  }
}
```

with javac full version "10.0.2+13"

  private void lambda$f$0();
    descriptor: ()V
    flags: (0x1002) ACC_PRIVATE, ACC_SYNTHETIC
    Code:
      stack=1, locals=1, args_size=1
         0: aload_0
         1: invokevirtual #3 // Method c:()LT$I;
         4: invokeinterface #4, 1 // InterfaceMethod T$I.d:()Ljava/lang/Object;
         9: checkcast #5 // class java/lang/Long
        12: pop
        13: return
      LineNumberTable:
        line 10: 0

with javac full version "11.0.2+9" (and newer):

  private void lambda$f$0();
    descriptor: ()V
    flags: (0x1002) ACC_PRIVATE, ACC_SYNTHETIC
    Code:
      stack=1, locals=1, args_size=1
         0: aload_0
         1: invokevirtual #3 // Method c:()LT$I;
         4: invokeinterface #4, 1 // InterfaceMethod T$I.d:()Ljava/lang/Object;
         9: pop
        10: return
      LineNumberTable:
        line 10: 0