[Test] Move KotlinAgainstKotlin tests under BlackBoxCodegen tests

compiler/testData/codegen/box/compileKotlinAgainstKotlin/jvm8/jvm8against6/simpleCall.kt

@@ -0,0 +1,21 @@
+// MODULE: lib
+// FILE: 1.kt
+
+interface Test {
+    fun test(): String {
+        return "OK"
+    }
+}
+
+// MODULE: main(lib)
+// FILE: 2.kt
+// JVM_TARGET: 1.8
+class TestClass : Test {
+    override fun test(): String {
+        return super.test()
+    }
+}
+
+fun box(): String {
+    return TestClass().test()
+}