Generate private constructors for enums in coverter

j2k/testData/fileOrElement/enum/constantsWithBody2.kt

@@ -1,5 +1,5 @@
 // ERROR: Cannot access 'p': it is 'invisible_fake' in 'A'
-public enum class E(private val p: Int) {
+public enum class E private constructor(private val p: Int) {
     A(1) {
         override fun bar() {
             foo(this.p)
@@ -15,4 +15,4 @@ public enum class E(private val p: Int) {
     }
 
     abstract fun bar()
-}
+}