Update docs

Author: anatoliykmetyuk

docs/docs/reference/enums/desugarEnums.md

@@ -170,8 +170,8 @@ Companion objects of enumerations that contain at least one simple case define i
      ordinal number and name. This method can be thought as being defined as
      follows.
 
-         private def $new(\_$ordinal: Int, $name: String) = new E {
-           def $ordinal = $tag
+         private def $new(_$ordinal: Int, $name: String) = new E {
+           def $ordinal = $_ordinal
            override def toString = $name
            $values.register(this) // register enum value so that `valueOf` and `values` can return it.
          }
@@ -186,6 +186,14 @@ identifiers.
 Even though translated enum cases are located in the enum's companion object, referencing
 this object or its members via `this` or a simple identifier is also illegal. The compiler typechecks enum cases in the scope of the enclosing companion object but flags any such illegal accesses as errors.
 
+### Translation of Java-compatible enums
+A Java-compatible enum is an enum that extends `java.lang.Enum`. The translation rules are the same as above, with the reservations defined in this section.
+
+It is a compile-time error for a Java-compatible enum to have class cases.
+
+Cases such as `case C` expand to a `@static val` as opposed to a `val`. This allows them to be generated as static fields of the enum type, thus ensuring they are represented the same way as Java enums.
+
+
 ### Other Rules
 
 A normal case class which is not produced from an enum case is not allowed to extend

docs/docs/reference/enums/enums.md

@@ -89,13 +89,13 @@ object Planet {
 ```
 
 ### Compatibility with Java Enums
-If you want to use the Scala-defined enums as Java enums, you can do so by extending `compat.JEnum` class as follows:
+If you want to use the Scala-defined enums as Java enums, you can do so by extending `java.lang.Enum` class as follows:
 
 ```scala
-enum Color extends compat.JEnum[Color] { case Red, Green, Blue }
+enum Color extends java.lang.Enum[Color] { case Red, Green, Blue }
 ```
 
-The type parameter comes from the Java enum [definition](https://docs.oracle.com/javase/8/docs/api/index.html?java/lang/Enum.html) and should me the same as the type of the enum. The compiler will transform the definition above so that `Color` extends `java.lang.Enum`.
+The type parameter comes from the Java enum [definition](https://docs.oracle.com/javase/8/docs/api/index.html?java/lang/Enum.html) and should be the same as the type of the enum. There is no need to provide constructor arguments (as defined in the API docs) to `java.lang.Enum` when extending it – the compiler will generate them automatically.
 
 After defining `Color` like that, you can use like you would a Java enum:
 
@@ -104,6 +104,8 @@ scala> Color.Red.compareTo(Color.Green)
 val res15: Int = -1
 ```
 
+For a more in-depth example of using Scala 3 enums from Java, see [this test](https://github.com/lampepfl/dotty/tree/master/tests/run/enum-java). In the test, the enums are defined in the `MainScala.scala` file and used from a Java source, `Test.java`.
+
 ### Implementation
 
 Enums are represented as `sealed` classes that extend the `scala.Enum` trait.