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/classes/kt1538.kt

@@ -0,0 +1,21 @@
+data class Pair<First, Second>(val first: First, val second: Second)
+
+fun parseCatalogs(hashMap: Any?) {
+    val r = toHasMap(hashMap)
+    if (!r.first) {
+        return
+    }
+    val nodes = r.second
+}
+
+fun toHasMap(value: Any?): Pair<Boolean, HashMap<String, Any?>?> {
+    if(value is HashMap<*, *>) {
+        return Pair(true, value as HashMap<String, Any?>)
+    }
+    return Pair(false, null as HashMap<String, Any?>?)
+}
+
+fun box() : String {
+    parseCatalogs(null)
+    return "OK"
+}