Fix visibility of protected classes in bytecode

Protected should be translated to public as in Java so that everything would
work at runtime. The real visibility is still saved to an InnerClasses
attribute

 #KT-8269 Fixed
 #KT-9246 Fixed
 #KT-10143 Fixed

compiler/testData/codegen/box/regressions/kt10143.kt

@@ -0,0 +1,33 @@
+// FILE: Outer.kt
+
+package another
+open class Outer {
+    protected class Stage(val run: () -> Unit)
+    protected class My(var stage: Stage? = null) {
+        fun initStage(f: () -> Unit): Stage {
+            stage = Stage(f)
+            return stage!!
+        }
+    }
+    protected fun my(init: My.() -> Unit): My {
+        val result = My()
+        result.init()
+        return result
+    }
+}
+
+// FILE: Main.kt
+
+package other
+class Derived : another.Outer() {
+    init {
+        my {
+            initStage { }
+        }
+    }
+}
+
+fun box(): String {
+    Derived()
+    return "OK"
+}