backend/tests: Add blackbox tests from Kotlin JVM

Added tests from testData/codegen/box directory. There are blackbox tests
in other directories and they are to be added.

backend.native/tests/external/codegen/blackbox/javaInterop/objectMethods/cloneHashSet.kt

@@ -0,0 +1,12 @@
+// TARGET_BACKEND: JVM
+
+fun box(): String {
+    val a = HashSet<String>()
+    a.add("live")
+    a.add("long")
+    a.add("prosper")
+    val b = a.clone()
+    if (a != b) return "Fail equals"
+    if (a === b) return "Fail identity"
+    return "OK"
+}