JVM: no nullability annotations on private and synthetic fields

plugins/allopen/allopen-cli/testData/bytecodeListing/anonymousObject.txt

@@ -28,7 +28,7 @@ final class Test$b$2 {
 @AllOpen
 @kotlin.Metadata
 public class Test {
-    private final @org.jetbrains.annotations.NotNull field a: java.lang.Runnable
+    private final field a: java.lang.Runnable
     inner class Test$a$1
     inner class Test$b$1
     inner class Test$b$2