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/objects/localFunctionInObjectInitializer_kt4516.kt

@@ -0,0 +1,17 @@
+
+object O {
+    val mmmap = HashMap<String, Int>();
+
+    init {
+        fun doStuff() {
+            mmmap.put("two", 2)
+        }
+        doStuff()
+    }
+}
+
+fun box(): String {
+    val r = O.mmmap["two"]
+    if (r != 2) return "Fail: $r"
+    return "OK"
+}