[Test] Move KotlinAgainstKotlin tests under BlackBoxCodegen tests

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

@@ -0,0 +1,19 @@
+// MODULE: lib
+// FILE: 1.kt
+
+interface Test {
+    val test: String
+        get() = "OK"
+}
+
+// MODULE: main(lib)
+// FILE: 2.kt
+// JVM_TARGET: 1.8
+class TestClass : Test {
+    override val test: String
+        get() = super.test
+}
+
+fun box(): String {
+    return TestClass().test
+}