[Test] Move KotlinAgainstKotlin tests under BlackBoxCodegen tests

compiler/testData/codegen/box/compileKotlinAgainstKotlin/internalSetterOverridden.kt

@@ -0,0 +1,18 @@
+// MODULE: lib
+// FILE: A.kt
+abstract class Base {
+    abstract var x: String
+        internal set
+}
+
+class Derived: Base() {
+    override var x: String = "Z"
+}
+
+// MODULE: main(lib)
+// FILE: B.kt
+fun box(): String {
+    val d = Derived()
+    d.x = "OK"
+    return d.x
+}