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/closures/localFunctionInFunction.kt

@@ -0,0 +1,14 @@
+fun box(): String {
+
+  fun local():Int {
+    return 10;
+  }
+
+  class A {
+      fun test(): Int {
+          return local()
+      }
+  }
+
+  return if (A().test() == 10) "OK" else "fail"
+}